European Journal of Clinical Nutrition (2014) 68, 282–283 & 2014 Macmillan Publishers Limited All rights reserved 0954-3007/14 www.nature.com/ejcn
RESPONSE TO LETTER TO THE EDITOR
Response to Dr Andersen et al. European Journal of Clinical Nutrition (2014) 68, 282–283; doi:10.1038/ejcn.2013.245; published online 4 December 2013
Table 1.
(Continued ) n (%)
Rapid weight gain (4 þ 1 s.d.) Yes No Rapid weight gain (4 þ 2 s.d.) Yes No Body fat (percentile)21 o2 2B25 25B50 50B75 75B85 X85 Fat mass % BMI (z-score)25 o 2 s.d. 2 to 1 s.d. 1 to 0 s.d. 0B1 s.d. 1B2 s.d. 42 s.d. BMI (kg/m2) Waist circumference (percentile)24 410 10B25 25B50 50B75 75B85 X85 Waist circumference Neck circumference18 Normal Overweight/Obesity Neck circumference Breastfeeding (months)* 0 0B3 3B6 6B12 12B24 X24 Physical activity Yes No
We are grateful to the colleagues from the Federal University of Sa˜o Paulo and Marilia Medical School, Brazil, for their suggestion to investigate sleep duration in future studies.1 However, the association between sleep duration and obesity has not been fully understood and supported by prospective epidemiological studies.2,3 Cappuccio et al.4 based on a metaanalysis involving 30 002 children and 604 509 adults did not confirm a causal inference between sleep disturbances and obesity due to lack of control of important confounders and inconsistent evidence of temporal sequence in prospective studies. The relationship was confirmed in cross-sectional studies, although a large representative sample of 102 353 US children from the National Survey of Children’s Health failed to reveal any independent association between insufficient sleep and childhood obesity.5 The relationship among sleep, sedentary behavior and hormonal levels should be assessed in detail, in prospective studies, to understand how those factors may affect obesity. Moreover, Touchette et al.6 recommends investigation on valid measurement tools to accurately seize duration as well as quality of sleep. According to Must and Parisi,3 further delineation of the complex interrelation of sleep, time use, mood, and familial aspects in racially and economically diverse samples are needed before sleep interventions can be designed or preventive guidance offered. On the other hand, Kim et al.7 argued that obstructive sleep apnea syndrome (OSAS) is an increasingly common health problem in children, and in the last decade, the emergence of increasing obesity rates has further led to remarkable increases in the prevalence of OSAS. Therefore, in a review, the author explored potential interactions between OSAS and obesity suggesting that this important health problem in children can also mediate the relationship between sleep duration and obesity and should be investigated. Apparently, several factors may interfere on sleep duration with a probable impact on child obesity. Among those factors, TV, mobile phones, electronic devices such as computers, video
Table 1.
Characteristics of the children and respective mothers
(n ¼ 98) n (%) Children Gender Male Female Birthweight (kg) o3 kg X3 kg Rapid weight gain (4 þ 0.67 s.d.) Yes No
Mean (s.d.)
43 (43.9) 55 (56.1) 3.3 (0.52) 22 (22.4) 76 (77.6) 60 (61.2) 38 (38.8)
Mothers Age at birth of the child (years)y p 19 20B30 30B40 40B45 Obesity Yes No Education (years) o4 4B8 8B11 11B17 21
Mean (s.d.)
50 (51.0) 48 (49.0) 21 (21.4) 77 (78.6) 3 3 13 23 14 42
(3.1) (3.1) (13.3) (23.5) (14.3) (42.8) 20.2 (4.9)
1 10 24 40 14 9
(1.0) (10.2) (24.5) (40.8) (14.3) (9.1) 16.2 (2.5)
4 10 24 33 10 17
(4.1) (10.2) (24.5) (33.7) (10.2) (17.3) 56.4 (7.1)
79 (80.6) 19 (19.4) 26.1 (1.9) 13.5 (14.1) 12 12 11 28 9 24 83 (84.7) 15 (15.3) 26.1 (6.4) 11 62 20 4
(11.2) (63.3) (20.4) (4.1)
17 (17.3) 81(82.7) 6.9 (4.1) 18 45 28 7
(18.4) (45.9) (28.6) (7.1)
McCarthy et al., 2006; 25WHO, 2006; 24McDowell et al., 2008; 18Nafiu et al., 2010. *n ¼ 96; yn ¼ 97.
Letter
283 games and other electronic gadgetry, particularly in the bedroom of the children, can interfere with their sleep duration.8–11 Nevertheless, the children included in the study by Sacco et al.12 are from Capa˜o Bonito, a small town in the poorest region of Sa˜o Paulo state, near Ribeira valley, where one in every four people live in rural areas and children have enough space to play outside home, with not much access to electronic media. Variables related to antenatal care, as suggested by the colleagues, were investigated by Sacco et al., as well as data regarding breastfeeding (shown in Table 1) and actual food intake (assessed by a food frequency questionnaire (FFQ)). Only 0.8% of the women included in the study did not take antenatal care. Breastfeeding was considered as a confounder, and did not show statistically significant associations with the outcomes of interest, as has been emphasized by Sacco et al.12 Data from the FFQ have been analyzed, although these data are not related to the objective of the present study. In summary, we believe that the relationship between sleep duration/quality and obesity is an important area for research, and we congratulate the colleagues for their choice. CONFLICT OF INTEREST The authors declare no conflict of interest.
MR Sacco1, NP de Castro1, VLV Euclydes1, JM Souza2 and PHC Rondo´1 1 Department of Nutrition, School of Public Health, University of Sa˜o Paulo, Sa˜o Paulo, Brazil and 2 Department of Epidemiology, School of Public Health, University of Sa˜o Paulo, Sa˜o Paulo, Brazil E-mail: [email protected].
& 2014 Macmillan Publishers Limited
REFERENCES 1 Boin AC, Nozoe KT, Polesel DN, Andersen ML, Tufik S. The possible influence of sleep in childhood obesity. Eur J Clin Nutr 2013; e-pub ahead of print 4 December 2013; doi:10.1038/ejcn.2013.247. 2 Landhuis CE, Poulton R, Welch D, Hancox RJ. Childhood sleep time and long-term risk for obesity: a 32-year prospective birth cohort study. Pediatrics 2008; 122: 955–960. 3 Must A, Parisi SM. Sedentary behavior and sleep: paradoxical effects in association with childhood obesity. Int J Obes 2009; 33(Suppl 1): S82–S86. 4 Cappuccio FP, Taggart FM, Ngianga-Bakwin Kandala, Currie A, Ed Peile, Stranges S et al. Meta-analysis of short sleep duration and obesity in children and adults. Sleep 2008; 31: 619–626. 5 Hassan F, Davis MM, Chervin RD. No independent association between insufficient sleep and childhood obesity in the National Survey of Children’s Health. J Clin Sleep Med 2011; 7: 153–157. 6 Touchette E, Petit D, Tremblay RE, Boivin M, Falissard B, Genolini C et al. Associations between sleep duration patterns and overweight/obesity at age 6. Sleep 2008; 31: 1507–1514. 7 Kim J, Hakim F, Kheirandish-Gozal L, Gozal D. Inflammatory pathways in children with insufficient or disordered sleep. Respir Physiol Neurobiol 2011; 178: 465–474. 8 Sekine M, Yamagami T, Handa K, Saito T, Nanri S, Kawaminami K et al. A dose-response relationship between short sleeping hours and childhood obesity: results of the Toyama Birth Cohort Study. Child Care Health Dev 2002; 28: 163–170. 9 Li S, Li S, Jin X, Wu S, Jiang F, Yan C et al. The impact of media use on sleep patterns and sleep disorders among school-aged children in China. Sleep 30: 361–367. 10 Gozal D, Kheirandish-Gozal L. Childhood obesity and sleep: relatives, partners, or both? – a critical perspective on the evidence. Ann N Y Acad Sci 2012; 1264: 135–141. 11 Haines J, McDonald J, O’Brien A, Sherry B, Bottino CJ, Schmidt ME et al. Healthy habits, happy homes: randomized trial to improve household routines for obesity prevention among preschool-aged children. JAMA Pediatr 2013; 167: 1072–1079. 12 Sacco MR, de Castro NP, Euclydes VLV, Souza JM, Rondo´ PHC. Birth weight, rapid weight gain in infancy and markers of overweight and obesity in childhood. Eur J Clin Nutr 2013; 67: 1147–1153.
European Journal of Clinical Nutrition (2014) 282 – 283
RESPONSE TO LETTER TO THE EDITOR
Response to Dr Andersen et al. European Journal of Clinical Nutrition (2014) 68, 282–283; doi:10.1038/ejcn.2013.245; published online 4 December 2013
Table 1.
(Continued ) n (%)
Rapid weight gain (4 þ 1 s.d.) Yes No Rapid weight gain (4 þ 2 s.d.) Yes No Body fat (percentile)21 o2 2B25 25B50 50B75 75B85 X85 Fat mass % BMI (z-score)25 o 2 s.d. 2 to 1 s.d. 1 to 0 s.d. 0B1 s.d. 1B2 s.d. 42 s.d. BMI (kg/m2) Waist circumference (percentile)24 410 10B25 25B50 50B75 75B85 X85 Waist circumference Neck circumference18 Normal Overweight/Obesity Neck circumference Breastfeeding (months)* 0 0B3 3B6 6B12 12B24 X24 Physical activity Yes No
We are grateful to the colleagues from the Federal University of Sa˜o Paulo and Marilia Medical School, Brazil, for their suggestion to investigate sleep duration in future studies.1 However, the association between sleep duration and obesity has not been fully understood and supported by prospective epidemiological studies.2,3 Cappuccio et al.4 based on a metaanalysis involving 30 002 children and 604 509 adults did not confirm a causal inference between sleep disturbances and obesity due to lack of control of important confounders and inconsistent evidence of temporal sequence in prospective studies. The relationship was confirmed in cross-sectional studies, although a large representative sample of 102 353 US children from the National Survey of Children’s Health failed to reveal any independent association between insufficient sleep and childhood obesity.5 The relationship among sleep, sedentary behavior and hormonal levels should be assessed in detail, in prospective studies, to understand how those factors may affect obesity. Moreover, Touchette et al.6 recommends investigation on valid measurement tools to accurately seize duration as well as quality of sleep. According to Must and Parisi,3 further delineation of the complex interrelation of sleep, time use, mood, and familial aspects in racially and economically diverse samples are needed before sleep interventions can be designed or preventive guidance offered. On the other hand, Kim et al.7 argued that obstructive sleep apnea syndrome (OSAS) is an increasingly common health problem in children, and in the last decade, the emergence of increasing obesity rates has further led to remarkable increases in the prevalence of OSAS. Therefore, in a review, the author explored potential interactions between OSAS and obesity suggesting that this important health problem in children can also mediate the relationship between sleep duration and obesity and should be investigated. Apparently, several factors may interfere on sleep duration with a probable impact on child obesity. Among those factors, TV, mobile phones, electronic devices such as computers, video
Table 1.
Characteristics of the children and respective mothers
(n ¼ 98) n (%) Children Gender Male Female Birthweight (kg) o3 kg X3 kg Rapid weight gain (4 þ 0.67 s.d.) Yes No
Mean (s.d.)
43 (43.9) 55 (56.1) 3.3 (0.52) 22 (22.4) 76 (77.6) 60 (61.2) 38 (38.8)
Mothers Age at birth of the child (years)y p 19 20B30 30B40 40B45 Obesity Yes No Education (years) o4 4B8 8B11 11B17 21
Mean (s.d.)
50 (51.0) 48 (49.0) 21 (21.4) 77 (78.6) 3 3 13 23 14 42
(3.1) (3.1) (13.3) (23.5) (14.3) (42.8) 20.2 (4.9)
1 10 24 40 14 9
(1.0) (10.2) (24.5) (40.8) (14.3) (9.1) 16.2 (2.5)
4 10 24 33 10 17
(4.1) (10.2) (24.5) (33.7) (10.2) (17.3) 56.4 (7.1)
79 (80.6) 19 (19.4) 26.1 (1.9) 13.5 (14.1) 12 12 11 28 9 24 83 (84.7) 15 (15.3) 26.1 (6.4) 11 62 20 4
(11.2) (63.3) (20.4) (4.1)
17 (17.3) 81(82.7) 6.9 (4.1) 18 45 28 7
(18.4) (45.9) (28.6) (7.1)
McCarthy et al., 2006; 25WHO, 2006; 24McDowell et al., 2008; 18Nafiu et al., 2010. *n ¼ 96; yn ¼ 97.
Letter
283 games and other electronic gadgetry, particularly in the bedroom of the children, can interfere with their sleep duration.8–11 Nevertheless, the children included in the study by Sacco et al.12 are from Capa˜o Bonito, a small town in the poorest region of Sa˜o Paulo state, near Ribeira valley, where one in every four people live in rural areas and children have enough space to play outside home, with not much access to electronic media. Variables related to antenatal care, as suggested by the colleagues, were investigated by Sacco et al., as well as data regarding breastfeeding (shown in Table 1) and actual food intake (assessed by a food frequency questionnaire (FFQ)). Only 0.8% of the women included in the study did not take antenatal care. Breastfeeding was considered as a confounder, and did not show statistically significant associations with the outcomes of interest, as has been emphasized by Sacco et al.12 Data from the FFQ have been analyzed, although these data are not related to the objective of the present study. In summary, we believe that the relationship between sleep duration/quality and obesity is an important area for research, and we congratulate the colleagues for their choice. CONFLICT OF INTEREST The authors declare no conflict of interest.
MR Sacco1, NP de Castro1, VLV Euclydes1, JM Souza2 and PHC Rondo´1 1 Department of Nutrition, School of Public Health, University of Sa˜o Paulo, Sa˜o Paulo, Brazil and 2 Department of Epidemiology, School of Public Health, University of Sa˜o Paulo, Sa˜o Paulo, Brazil E-mail: [email protected].
& 2014 Macmillan Publishers Limited
REFERENCES 1 Boin AC, Nozoe KT, Polesel DN, Andersen ML, Tufik S. The possible influence of sleep in childhood obesity. Eur J Clin Nutr 2013; e-pub ahead of print 4 December 2013; doi:10.1038/ejcn.2013.247. 2 Landhuis CE, Poulton R, Welch D, Hancox RJ. Childhood sleep time and long-term risk for obesity: a 32-year prospective birth cohort study. Pediatrics 2008; 122: 955–960. 3 Must A, Parisi SM. Sedentary behavior and sleep: paradoxical effects in association with childhood obesity. Int J Obes 2009; 33(Suppl 1): S82–S86. 4 Cappuccio FP, Taggart FM, Ngianga-Bakwin Kandala, Currie A, Ed Peile, Stranges S et al. Meta-analysis of short sleep duration and obesity in children and adults. Sleep 2008; 31: 619–626. 5 Hassan F, Davis MM, Chervin RD. No independent association between insufficient sleep and childhood obesity in the National Survey of Children’s Health. J Clin Sleep Med 2011; 7: 153–157. 6 Touchette E, Petit D, Tremblay RE, Boivin M, Falissard B, Genolini C et al. Associations between sleep duration patterns and overweight/obesity at age 6. Sleep 2008; 31: 1507–1514. 7 Kim J, Hakim F, Kheirandish-Gozal L, Gozal D. Inflammatory pathways in children with insufficient or disordered sleep. Respir Physiol Neurobiol 2011; 178: 465–474. 8 Sekine M, Yamagami T, Handa K, Saito T, Nanri S, Kawaminami K et al. A dose-response relationship between short sleeping hours and childhood obesity: results of the Toyama Birth Cohort Study. Child Care Health Dev 2002; 28: 163–170. 9 Li S, Li S, Jin X, Wu S, Jiang F, Yan C et al. The impact of media use on sleep patterns and sleep disorders among school-aged children in China. Sleep 30: 361–367. 10 Gozal D, Kheirandish-Gozal L. Childhood obesity and sleep: relatives, partners, or both? – a critical perspective on the evidence. Ann N Y Acad Sci 2012; 1264: 135–141. 11 Haines J, McDonald J, O’Brien A, Sherry B, Bottino CJ, Schmidt ME et al. Healthy habits, happy homes: randomized trial to improve household routines for obesity prevention among preschool-aged children. JAMA Pediatr 2013; 167: 1072–1079. 12 Sacco MR, de Castro NP, Euclydes VLV, Souza JM, Rondo´ PHC. Birth weight, rapid weight gain in infancy and markers of overweight and obesity in childhood. Eur J Clin Nutr 2013; 67: 1147–1153.
European Journal of Clinical Nutrition (2014) 282 – 283
