1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54
YCLNU2578_proof ■ 29 May 2015 ■ 1/8
Clinical Nutrition xxx (2015) 1e8
Contents lists available at ScienceDirect
Clinical Nutrition journal homepage: http://www.elsevier.com/locate/clnu
Randomized control trials
Q4 Q3
Chronic consumption of an inositol-enriched carob extract improves postprandial glycaemia and insulin sensitivity in healthy subjects: A randomized controlled trial ~ uls a, b, Susana Rovira-Llopis a, b, Rosa Falco n a, Silvia Veses a, Nuria Monzo a, c, Celia Ban a, b, d, e a, b, d, * a , b , c , * ndez-Mijares , Milagros Rocha , Antonio Herna Víctor M. Víctor a
Service of Endocrinology, University Hospital Dr. Peset, Foundation for the Promotion of Health and Biomedical Research in the Valencian Region (FISABIO), Avda. Gaspar Aguilar 90, 46017 Valencia, Spain n ~ ez 17, 46010 Valencia, Spain Institute of Health Research INCLIVA, Av Blasco Iba c n ~ ez 13, 46010 Valencia, Spain Department of Medicine, Faculty of Medicine, University of Valencia, Av Blasco Iba d n ~ ez 13, 46010 Valencia, Spain CIBER CB06/04/0071 Research Group, CIBER Hepatic and Digestive Diseases, University of Valencia, Av Blasco Iba e n ~ ez 13, 46010 Valencia, Spain Department of Physiology, Faculty of Medicine, University of Valencia, Av Blasco Iba b
a r t i c l e i n f o
s u m m a r y
Article history: Received 18 February 2015 Accepted 13 May 2015
Background & aims: Inositols are thought to be mediators of the insulin signalling pathway. We assessed the effects of inositols on glycaemic control in fasting and postprandial states and evaluated lipoprotein profile and LDL particle size in healthy population. Methods: A 12-week double-blind clinical trial was performed with forty healthy subjects administered either an inositol-enriched beverage (IEB) -containing 2.23 g of inositols in 250 ml- or a sucrosesweetened beverage (SB) twice a day. Anthropometric measurements, fasting glucose levels, insulin and HOMA-IR index, lipoprotein profile and postprandial glucose concentrations (measured using the continuous glucose monitoring system (CGMS)) were recorded throughout the intervention period. Results: Following the 12-week trial subjects receiving the IEB exhibited a significant decrease in insulin, HOMA-IR and Apo B and an increase in LDL particle size, whereas the SB group showed increases in BMI and fasting glucose concentration. Analysis of postprandial glucose levels at breakfast, lunch and dinner revealed a mean reduction of glucose of z14% and a significant reduction in the area under the curve at 24 h after consumption of the IEB. Conclusions: Our results show that chronic IEB supplementation induces a significant improvement in carbohydrated metabolism parameters in healthy subjects. © 2015 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.
Keywords: Carob pod extract Inositols Pinitol Continuous glucose monitoring system Healthy subjects LDL particle size
1. Introduction Several epidemiological studies in predominantly non-diabetic populations have shown that the relationship between glycaemia and cardiovascular disease is a continuum that begins within a
Abbreviations: CGMS, continuous glucose monitoring system; HOMA-IR, homeostasis model assessment of insulin resistance; IEB, inositol-enriched beverage; SB, sucrose-sweetened beverage. * Corresponding authors. Service of Endocrinology, University Hospital Dr. Peset, Av. Gaspar Aguilar 90, 46017 Valencia, Spain. Tel./fax: þ34 961622492. E-mail addresses: [email protected] (M. Rocha), [email protected] (A. Hern andez-Mijares).
normal range of glucose tolerance that rises as glycaemia increases [1]. The relevance of postprandial glycaemia with respect to cardiovascular risk was evaluated in the DECODE study, a metaanalysis of an asymptomatic population which found that mortality was significantly related to high glucose concentrations 2 h after a glucose load, independent of fasting glucose levels [2]. In NHANES II, isolated post-load hyperglycaemia was again found to be associated with higher rates of all-cause and cardiovascular mortality [3]. Given that it is during the postprandial period that plasma glucose is at its highest, it would be logical to assume that life-style changes that specifically lower glycaemia levels at this time are beneficial. The continuous glucose monitoring system (CGMS),
http://dx.doi.org/10.1016/j.clnu.2015.05.005 0261-5614/© 2015 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.
~ uls C, et al., Chronic consumption of an inositol-enriched carob extract improves postprandial glycaemia Please cite this article in press as: Ban and insulin sensitivity in healthy subjects: A randomized controlled trial, Clinical Nutrition (2015), http://dx.doi.org/10.1016/j.clnu.2015.05.005
55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
YCLNU2578_proof ■ 29 May 2015 ■ 2/8
~ uls et al. / Clinical Nutrition xxx (2015) 1e8 C. Ban
2
which measures interstitial glucose concentrations, is increasingly used in clinical practice and clinical research to monitor diabetic patients. Several studies using CGMS have demonstrated that a simple change in the diet of a healthy subject e namely the incorporation of a low-glycaemic index key food e improves the glucose profile and reduces the risk of cardiovascular disease [4,5]. The growing interest in metabolic medicine as a tool to combat major disorders such as obesity and diabetes, has resulted in an increased output of research and development regarding bioactive carbohydrates dietary, particularly polyols, fibre and related carbohydrates. Polyols as sugar replacers have been reported to have antidiabetic activity in different experimental models [6]. Recent evidence published by our group has shown that tolerance to glucose and sensitivity to insulin are altered by acute consumption of a carob pod extract containing bioactive carbohydrates and pinitol in healthy subjects [7]. Pinitol (3-O-methyl-D-chiro-inositol) is thought to be a mediator of the insulin signalling pathway and to be involved in glycosylphosphatidil-inositol protein anchors [8]. Some studies have explored how continued pinitol supplementation can alter glycaemic control, but the results obtained do not provide a clear picture. Moreover, most of these previous reports employed populations with diabetes or intolerance to glucose [9e12], and only one evaluated healthy subjects [13]. Dietary supplementation with pinitol has been shown to improve glycaemic control during fasting and following the oral glucose tolerance test or the euglycaemic hyperinsulinemic clamp in a number of papers [9e11], while no effect has been observed in other reports [12,13]. In any case, none of these studies has evaluated the effect of inositols on postprandial glycaemic response, lipoprotein profile or LDL particle size in healthy subjects under free-living conditions. We have previously published evidence of an increase in small and dense LDL particles in subjects with insulin resistance [14,15] that correlated with the progression of atherosclerosis and earlier and more severe cardiovascular disease [16,17]. Therefore, the primary aim of the present study was to assess the chronic consumption of an oral nutritive inositol-enriched beverage (IEB) on glycaemia (in fasting and postprandial states), insulin levels and insulin resistance. A secondary objective was to investigate how this extract influences lipoprotein profile and LDL particle size in healthy subjects. 2. Material and methods 2.1. Subjects We enrolled forty-one volunteers in the study; these subjects were recruited from among patients' relatives and staff at the Endocrinology Outpatient's Clinic of the city of Valencia's University Hospital Dr. Peset from January 2012 to June 2013. Subjects were recruited if they fulfilled the following inclusion criteria: 19e64 years old; body mass index of 20e30 kg/m2; normal kidney, liver and heart function; normal protein status; and normal haematological profile. Potential subjects were excluded if pregnant or lactating; if they had fasting levels of glycaemia 100 mg/dl on at least two previous occasions, if diabetic; or if they were receiving medication that interfered with glucose metabolism. The study was performed in line with the Declaration of Helsinki, and our hospital's Ethics Committee approved all the procedures affecting the subjects. All patients provided written informed consent. One of the forty-one originally enrolled volunteers withdrew from the project due to personal reasons, because of an inability or unwillingness to comply with the protocol. The trial was registered in clinicaltrials.gov with study number NCT01754792.
2.2. Study design This was a randomised double-blind controlled trial. Before dietary therapy was initiated, subjects underwent a 1-month run-up period of a normocaloric diet in order to stabilise dietary patterns prior to intervention. After this adaptation period, subjects were randomly assigned to one of two groups which received either an IEB (n ¼ 20) or a matching sucrose-sweetened beverage (SB) (n ¼ 20) for 12 weeks. Subjects ingested 4.45 g (2.23 g, twice a day) of the IEB (Fruit Up®, a commercially available product consisting of natural ingredients) or an SB, and maintained a normocaloric diet throughout the study. During the course of the whole trial, an experienced dietician monitored the subjects, who were provided with written and oral instructions regarding their diet; i.e., the exact quantity and type of food products they should eat. In addition, subjects were instructed to continue with their normal daily routine. Depending on daily caloric expenditure, an average daily energy intake of 7118e9630 KJ (1700e2300 kcal) was recommended, of which 15e20% should have been proteins, 50e55% carbohydrates and 28e33% fats. During appointments with a dietician before the adaptation period at baseline, at 6 weeks and at termination of the study (12 weeks), adherence to the diet was monitored by means of 3-day food records (compiled on two weekdays and on one day during the weekend). The software NutrIber v1.1.3 (FUNIBER, Barcelona, Spain) was employed to calculate energy and nutrients according to food intake. Subjects were instructed to drink the beverage as part of their mid-morning and mid-afternoon snacks. Both the IEB containing Fruit Up® and the SB were supplied by Wild-Valencia SAU (Spain) in aluminium cans. The composition of Fruit Up® is as follows: naturally occurring soluble carbohydrates (mono-saccharides, disaccharides, oligo-saccharides, polyalcohols and soluble fibre) and minor compounds (in trace contents: organic acids, minerals, amino-acids) derived principally from carob pods. The SB contained similar amounts of total carbohydrates (41.25 vs 42.50 g) and total available carbohydrates (39.61 vs 42.50 g), which represents a net difference of 15 kcal (less than 1%) in total calories ingested. The intervention drinks were prepared by mixture 123.0 g of Fruit Up® 70 Brix per litre (IEB) and 126.7 g of liquid sucrose syrup 67 Brix per litre (SB). In addition, both drinks contained 2.3 g per litre of citric acid monohydrate (E-330), 1.3 g per litre of sodium citrate dehydrate (E-331), 0.35 g per litre of black carrot colour extract (natural colour E-163), 0.5 g per litre of strawberry flavouring (natural flavour) and 0.2 g per litre of potassium sorbate (E-202). The nutritional composition of the IEB with respect to the SB is shown in Table 1. The manufacturing process for obtaining the intervention drinks is enclosed as Supplementary data. We evaluated a series of anthropometrical parameters: weight was measured with electronic scales and rounded to the nearest 0.1 kg; height was recorded using a stadiometer and rounded to the nearest 0.5 cm; weight (in kg) was divided by the square of the height in meters to calculate BMI; blood pressure was measured twice by means of a sphygmomanometer; waist circumference (between the 10th rib and iliac crest) was recorded using a metric tape and rounded to the nearest 0.5 cm. 2.3. Blood sampling Venous blood samples were collected from patients at 8e10 a.m. after 12 h overnight fasting at baseline (t ¼ 0), in the middle (t ¼ 6 weeks) and at the end of the study (t ¼ 12 weeks). For the purpose of separating serum/plasma from blood, samples were centrifuged in Vacutainer® tubes for 15 min a 2000 g at a temperature of 4 C. Fresh samples were employed to determine fasting glucose, insulin
~ uls C, et al., Chronic consumption of an inositol-enriched carob extract improves postprandial glycaemia Please cite this article in press as: Ban and insulin sensitivity in healthy subjects: A randomized controlled trial, Clinical Nutrition (2015), http://dx.doi.org/10.1016/j.clnu.2015.05.005
66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
YCLNU2578_proof ■ 29 May 2015 ■ 3/8
~ uls et al. / Clinical Nutrition xxx (2015) 1e8 C. Ban Table 1 Nutritional composition of the main soluble carbohydrates contained in the inositolenriched beverage (IEB) and sucrose-sweetened beverage (SB) administered in the study, per day.
Pinitol (g) Myoinositol þ D-chiro-inositol (g) Other polyols (g) Xylitol Sorbitol Mannitol Sugars (g) Glucose Fructose Sucrose Other sugars Maltose Maltulose Gentibiose Arabinose Galactose Rhamnose Fucose Xylose Oligosaccharides (g) Maltotriose Maltotetraose Soluble fibre (g) Arabinoxylan Other soluble fibres Stachyose Raffinose Cellobiose Kestose Total carbohydrates (g) Total available carbohydrates (g) Total calorie (kcal)
IEB
SB
4.00 0.45 0.168 0.012 0.075 0.081 34.916 6.23 4.83 23.26 0.596 0.130 0.031 0.031 0.031 0.031 0.031 0.031 0.280 0.062 0.031 0.031 1.65 1.31 0.340 0.041 0.041 0.041 0.217 41.25 39.61 155.0
e e e
42.50 e e 42.50 e
e
42.50 42.50 170.0
An inositol-enriched beverage (IEB) (containing the commercial natural food ingredient Fruit Up®) or sucrose-sweetened beverage (SB) was consumed twice per day (250 ml on each occasion), during mid-morning and mid-afternoon snacks.
and lipoprotein levels. Serum aliquots were stored for subsequent measurement of LDL lipoprotein subfractions at 80 C. 2.4. Biochemical determinations A Beckman LX-20 autoanalyzer (Beckman Coulter, La Brea, CA, USA) was employed to perform enzymatic assays to measure glucose concentrations, while enzymatic luminescence was employed to measure insulin. Homeostasis model assessment (HOMA-IR ¼ (fasting insulin (mU/mL) fasting glucose (mg/dl)/ 405) was used to calculate insulin resistance. Total cholesterol and triglycerides were measured by means of enzymatic assays, and HDLc concentrations were recorded with a Beckman LX-20 autoanalyzer (Beckman Coulter, La Brea, CA, USA) using a direct method. The intraserial variation coefficient was
YCLNU2578_proof ■ 29 May 2015 ■ 1/8
Clinical Nutrition xxx (2015) 1e8
Contents lists available at ScienceDirect
Clinical Nutrition journal homepage: http://www.elsevier.com/locate/clnu
Randomized control trials
Q4 Q3
Chronic consumption of an inositol-enriched carob extract improves postprandial glycaemia and insulin sensitivity in healthy subjects: A randomized controlled trial ~ uls a, b, Susana Rovira-Llopis a, b, Rosa Falco n a, Silvia Veses a, Nuria Monzo a, c, Celia Ban a, b, d, e a, b, d, * a , b , c , * ndez-Mijares , Milagros Rocha , Antonio Herna Víctor M. Víctor a
Service of Endocrinology, University Hospital Dr. Peset, Foundation for the Promotion of Health and Biomedical Research in the Valencian Region (FISABIO), Avda. Gaspar Aguilar 90, 46017 Valencia, Spain n ~ ez 17, 46010 Valencia, Spain Institute of Health Research INCLIVA, Av Blasco Iba c n ~ ez 13, 46010 Valencia, Spain Department of Medicine, Faculty of Medicine, University of Valencia, Av Blasco Iba d n ~ ez 13, 46010 Valencia, Spain CIBER CB06/04/0071 Research Group, CIBER Hepatic and Digestive Diseases, University of Valencia, Av Blasco Iba e n ~ ez 13, 46010 Valencia, Spain Department of Physiology, Faculty of Medicine, University of Valencia, Av Blasco Iba b
a r t i c l e i n f o
s u m m a r y
Article history: Received 18 February 2015 Accepted 13 May 2015
Background & aims: Inositols are thought to be mediators of the insulin signalling pathway. We assessed the effects of inositols on glycaemic control in fasting and postprandial states and evaluated lipoprotein profile and LDL particle size in healthy population. Methods: A 12-week double-blind clinical trial was performed with forty healthy subjects administered either an inositol-enriched beverage (IEB) -containing 2.23 g of inositols in 250 ml- or a sucrosesweetened beverage (SB) twice a day. Anthropometric measurements, fasting glucose levels, insulin and HOMA-IR index, lipoprotein profile and postprandial glucose concentrations (measured using the continuous glucose monitoring system (CGMS)) were recorded throughout the intervention period. Results: Following the 12-week trial subjects receiving the IEB exhibited a significant decrease in insulin, HOMA-IR and Apo B and an increase in LDL particle size, whereas the SB group showed increases in BMI and fasting glucose concentration. Analysis of postprandial glucose levels at breakfast, lunch and dinner revealed a mean reduction of glucose of z14% and a significant reduction in the area under the curve at 24 h after consumption of the IEB. Conclusions: Our results show that chronic IEB supplementation induces a significant improvement in carbohydrated metabolism parameters in healthy subjects. © 2015 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.
Keywords: Carob pod extract Inositols Pinitol Continuous glucose monitoring system Healthy subjects LDL particle size
1. Introduction Several epidemiological studies in predominantly non-diabetic populations have shown that the relationship between glycaemia and cardiovascular disease is a continuum that begins within a
Abbreviations: CGMS, continuous glucose monitoring system; HOMA-IR, homeostasis model assessment of insulin resistance; IEB, inositol-enriched beverage; SB, sucrose-sweetened beverage. * Corresponding authors. Service of Endocrinology, University Hospital Dr. Peset, Av. Gaspar Aguilar 90, 46017 Valencia, Spain. Tel./fax: þ34 961622492. E-mail addresses: [email protected] (M. Rocha), [email protected] (A. Hern andez-Mijares).
normal range of glucose tolerance that rises as glycaemia increases [1]. The relevance of postprandial glycaemia with respect to cardiovascular risk was evaluated in the DECODE study, a metaanalysis of an asymptomatic population which found that mortality was significantly related to high glucose concentrations 2 h after a glucose load, independent of fasting glucose levels [2]. In NHANES II, isolated post-load hyperglycaemia was again found to be associated with higher rates of all-cause and cardiovascular mortality [3]. Given that it is during the postprandial period that plasma glucose is at its highest, it would be logical to assume that life-style changes that specifically lower glycaemia levels at this time are beneficial. The continuous glucose monitoring system (CGMS),
http://dx.doi.org/10.1016/j.clnu.2015.05.005 0261-5614/© 2015 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.
~ uls C, et al., Chronic consumption of an inositol-enriched carob extract improves postprandial glycaemia Please cite this article in press as: Ban and insulin sensitivity in healthy subjects: A randomized controlled trial, Clinical Nutrition (2015), http://dx.doi.org/10.1016/j.clnu.2015.05.005
55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
YCLNU2578_proof ■ 29 May 2015 ■ 2/8
~ uls et al. / Clinical Nutrition xxx (2015) 1e8 C. Ban
2
which measures interstitial glucose concentrations, is increasingly used in clinical practice and clinical research to monitor diabetic patients. Several studies using CGMS have demonstrated that a simple change in the diet of a healthy subject e namely the incorporation of a low-glycaemic index key food e improves the glucose profile and reduces the risk of cardiovascular disease [4,5]. The growing interest in metabolic medicine as a tool to combat major disorders such as obesity and diabetes, has resulted in an increased output of research and development regarding bioactive carbohydrates dietary, particularly polyols, fibre and related carbohydrates. Polyols as sugar replacers have been reported to have antidiabetic activity in different experimental models [6]. Recent evidence published by our group has shown that tolerance to glucose and sensitivity to insulin are altered by acute consumption of a carob pod extract containing bioactive carbohydrates and pinitol in healthy subjects [7]. Pinitol (3-O-methyl-D-chiro-inositol) is thought to be a mediator of the insulin signalling pathway and to be involved in glycosylphosphatidil-inositol protein anchors [8]. Some studies have explored how continued pinitol supplementation can alter glycaemic control, but the results obtained do not provide a clear picture. Moreover, most of these previous reports employed populations with diabetes or intolerance to glucose [9e12], and only one evaluated healthy subjects [13]. Dietary supplementation with pinitol has been shown to improve glycaemic control during fasting and following the oral glucose tolerance test or the euglycaemic hyperinsulinemic clamp in a number of papers [9e11], while no effect has been observed in other reports [12,13]. In any case, none of these studies has evaluated the effect of inositols on postprandial glycaemic response, lipoprotein profile or LDL particle size in healthy subjects under free-living conditions. We have previously published evidence of an increase in small and dense LDL particles in subjects with insulin resistance [14,15] that correlated with the progression of atherosclerosis and earlier and more severe cardiovascular disease [16,17]. Therefore, the primary aim of the present study was to assess the chronic consumption of an oral nutritive inositol-enriched beverage (IEB) on glycaemia (in fasting and postprandial states), insulin levels and insulin resistance. A secondary objective was to investigate how this extract influences lipoprotein profile and LDL particle size in healthy subjects. 2. Material and methods 2.1. Subjects We enrolled forty-one volunteers in the study; these subjects were recruited from among patients' relatives and staff at the Endocrinology Outpatient's Clinic of the city of Valencia's University Hospital Dr. Peset from January 2012 to June 2013. Subjects were recruited if they fulfilled the following inclusion criteria: 19e64 years old; body mass index of 20e30 kg/m2; normal kidney, liver and heart function; normal protein status; and normal haematological profile. Potential subjects were excluded if pregnant or lactating; if they had fasting levels of glycaemia 100 mg/dl on at least two previous occasions, if diabetic; or if they were receiving medication that interfered with glucose metabolism. The study was performed in line with the Declaration of Helsinki, and our hospital's Ethics Committee approved all the procedures affecting the subjects. All patients provided written informed consent. One of the forty-one originally enrolled volunteers withdrew from the project due to personal reasons, because of an inability or unwillingness to comply with the protocol. The trial was registered in clinicaltrials.gov with study number NCT01754792.
2.2. Study design This was a randomised double-blind controlled trial. Before dietary therapy was initiated, subjects underwent a 1-month run-up period of a normocaloric diet in order to stabilise dietary patterns prior to intervention. After this adaptation period, subjects were randomly assigned to one of two groups which received either an IEB (n ¼ 20) or a matching sucrose-sweetened beverage (SB) (n ¼ 20) for 12 weeks. Subjects ingested 4.45 g (2.23 g, twice a day) of the IEB (Fruit Up®, a commercially available product consisting of natural ingredients) or an SB, and maintained a normocaloric diet throughout the study. During the course of the whole trial, an experienced dietician monitored the subjects, who were provided with written and oral instructions regarding their diet; i.e., the exact quantity and type of food products they should eat. In addition, subjects were instructed to continue with their normal daily routine. Depending on daily caloric expenditure, an average daily energy intake of 7118e9630 KJ (1700e2300 kcal) was recommended, of which 15e20% should have been proteins, 50e55% carbohydrates and 28e33% fats. During appointments with a dietician before the adaptation period at baseline, at 6 weeks and at termination of the study (12 weeks), adherence to the diet was monitored by means of 3-day food records (compiled on two weekdays and on one day during the weekend). The software NutrIber v1.1.3 (FUNIBER, Barcelona, Spain) was employed to calculate energy and nutrients according to food intake. Subjects were instructed to drink the beverage as part of their mid-morning and mid-afternoon snacks. Both the IEB containing Fruit Up® and the SB were supplied by Wild-Valencia SAU (Spain) in aluminium cans. The composition of Fruit Up® is as follows: naturally occurring soluble carbohydrates (mono-saccharides, disaccharides, oligo-saccharides, polyalcohols and soluble fibre) and minor compounds (in trace contents: organic acids, minerals, amino-acids) derived principally from carob pods. The SB contained similar amounts of total carbohydrates (41.25 vs 42.50 g) and total available carbohydrates (39.61 vs 42.50 g), which represents a net difference of 15 kcal (less than 1%) in total calories ingested. The intervention drinks were prepared by mixture 123.0 g of Fruit Up® 70 Brix per litre (IEB) and 126.7 g of liquid sucrose syrup 67 Brix per litre (SB). In addition, both drinks contained 2.3 g per litre of citric acid monohydrate (E-330), 1.3 g per litre of sodium citrate dehydrate (E-331), 0.35 g per litre of black carrot colour extract (natural colour E-163), 0.5 g per litre of strawberry flavouring (natural flavour) and 0.2 g per litre of potassium sorbate (E-202). The nutritional composition of the IEB with respect to the SB is shown in Table 1. The manufacturing process for obtaining the intervention drinks is enclosed as Supplementary data. We evaluated a series of anthropometrical parameters: weight was measured with electronic scales and rounded to the nearest 0.1 kg; height was recorded using a stadiometer and rounded to the nearest 0.5 cm; weight (in kg) was divided by the square of the height in meters to calculate BMI; blood pressure was measured twice by means of a sphygmomanometer; waist circumference (between the 10th rib and iliac crest) was recorded using a metric tape and rounded to the nearest 0.5 cm. 2.3. Blood sampling Venous blood samples were collected from patients at 8e10 a.m. after 12 h overnight fasting at baseline (t ¼ 0), in the middle (t ¼ 6 weeks) and at the end of the study (t ¼ 12 weeks). For the purpose of separating serum/plasma from blood, samples were centrifuged in Vacutainer® tubes for 15 min a 2000 g at a temperature of 4 C. Fresh samples were employed to determine fasting glucose, insulin
~ uls C, et al., Chronic consumption of an inositol-enriched carob extract improves postprandial glycaemia Please cite this article in press as: Ban and insulin sensitivity in healthy subjects: A randomized controlled trial, Clinical Nutrition (2015), http://dx.doi.org/10.1016/j.clnu.2015.05.005
66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65
YCLNU2578_proof ■ 29 May 2015 ■ 3/8
~ uls et al. / Clinical Nutrition xxx (2015) 1e8 C. Ban Table 1 Nutritional composition of the main soluble carbohydrates contained in the inositolenriched beverage (IEB) and sucrose-sweetened beverage (SB) administered in the study, per day.
Pinitol (g) Myoinositol þ D-chiro-inositol (g) Other polyols (g) Xylitol Sorbitol Mannitol Sugars (g) Glucose Fructose Sucrose Other sugars Maltose Maltulose Gentibiose Arabinose Galactose Rhamnose Fucose Xylose Oligosaccharides (g) Maltotriose Maltotetraose Soluble fibre (g) Arabinoxylan Other soluble fibres Stachyose Raffinose Cellobiose Kestose Total carbohydrates (g) Total available carbohydrates (g) Total calorie (kcal)
IEB
SB
4.00 0.45 0.168 0.012 0.075 0.081 34.916 6.23 4.83 23.26 0.596 0.130 0.031 0.031 0.031 0.031 0.031 0.031 0.280 0.062 0.031 0.031 1.65 1.31 0.340 0.041 0.041 0.041 0.217 41.25 39.61 155.0
e e e
42.50 e e 42.50 e
e
42.50 42.50 170.0
An inositol-enriched beverage (IEB) (containing the commercial natural food ingredient Fruit Up®) or sucrose-sweetened beverage (SB) was consumed twice per day (250 ml on each occasion), during mid-morning and mid-afternoon snacks.
and lipoprotein levels. Serum aliquots were stored for subsequent measurement of LDL lipoprotein subfractions at 80 C. 2.4. Biochemical determinations A Beckman LX-20 autoanalyzer (Beckman Coulter, La Brea, CA, USA) was employed to perform enzymatic assays to measure glucose concentrations, while enzymatic luminescence was employed to measure insulin. Homeostasis model assessment (HOMA-IR ¼ (fasting insulin (mU/mL) fasting glucose (mg/dl)/ 405) was used to calculate insulin resistance. Total cholesterol and triglycerides were measured by means of enzymatic assays, and HDLc concentrations were recorded with a Beckman LX-20 autoanalyzer (Beckman Coulter, La Brea, CA, USA) using a direct method. The intraserial variation coefficient was
