J . ment. Defic. Res. (1976) 20, 9
OBESITY IN AN INSTITUTIONALISED ADULT MENTALLY RETARDED POPULATION A. P. POLEDNAK* and JAN AULIFFE Birth Defects Institute, State Department of Health, Albany, New Tork
Since the institution may be the only living environment for many retarded persons, an important consideration is the extent to which that environment is conducive to optimal health. Obesity is one health-related variable that is recognised as a major problem in the United States and Canada. The importance of obesity as a risk factor in chronic diseases is well documented; associations with diabetes (Paffenfarger and Wing, 1973), hypertension (Florey and Acheson, 1969; Goldman, Varady and Franklin, 1972) and cardio-vascular disease (Gordon and Kannel, 1973) have been confirmed by recent studies. There are few published studies on the frequency of obesity in institutionalised mentally retarded populations. Cumming, Goulding, and Baggley (1971) reported weight, height and body fat (based on skinfold measures) among sixty-seven retarded schoolchildren in Winnipeg, Manitoba. Compared with deaf and visually handicapped boys, retarded boys aged from thirteen to seventeen were heavier and slightly fatter. Retarded girls of the same group were considerably heavier and fatter than the other two groups. Skinfold data were not presented in terms of accepted obesity standards. In Uppsala, Sweden, various anthropometric measures were reported among thirty-nine male and twenty-four female retarded persons aged nineteen to thirty-nine (Nordgren, 1970). For the males, skinfolds were significantly greater in the retarded group compared with an unspecified normal population. These limited data indicate the need for studies of larger groups, using established indices of obesity. SUBJECTS AND METHOD Subjects were mentally retarded residents at the Oxford Mental Health Centre, Woodstock, Ontario. This facility was formerly a tuberculosis centre, but now provides services only for the retarded. Subjects in the present study included all residents of Activity Unit "A", comprising 161 adults. The age range was eighteen to seventy-three years. The sample included 108 males (mean age 39.9 ± 12.7 S.D. years) and fifty-three females (mean age 42.2 ± 15.5 S.D. years). The level of retardation ofthe subjects was as follows: for males, thirty-six mild, forty-two moderate, and thirty-one severe; and for females, fifteen mild, twenty-one moderate, and seventeen severe. Specific syndromes of mental retardation reported included Down's syndrome (thirteen cases or 7.6 per cent), tuberous sclerosis (one case), and phenylketonuria (one case). Medical histories were obtained from individual record files. All diseases or conditions were noted, as recorded at the last annual medical examination. Obesity *Present address: Centre for Human Radiobiology, Argonne National Laboratory, Argonne, Illinois 60439. Received 16th September, 1975
9
10
OBESITY
was also noted when it appeared on the medical record. These data should give a general indication of the health and nutritional status of the subjects. Triceps skinfold, upper arm circumference, height and weight were measured. Height was measured with the subject standing against a wall without shoes, and recorded to the nearest half-inch. Triceps skinfold was measured on the bare right arm, using a Harpenden caliper. Arm circumference was measured on the bare right arm, using a flexible steel tape. Weight was measured on a spring scale with subject wearing light indoor clothing. The best criteria for obesity involve skinfold measurements at selected sites (Mayer, 1968; Seltzer and Mayer, 1965, 1967; Seltzer, Stoudt, Bell and Mayer, 1970). Obesity standards based on triceps skinfold (Seltzer and Mayer, 1965) have been recommended for large field surveys and clinical work (U.S. Public Health, 1966), and have been used in the present study. These standards were derived from extensive data on the distribution of skinfolds in the American population. Arbitrary cut-ofT points were defined as triceps skinfold greater than the population mean by more than one standard deviation (Seltzer and Mayer, 1965). It should be noted that the triceps skinfold criteria are useful for screening purposes, but the obesity defined is not necessarily severe in clinical terms or in relation to risk of specific diseases. Differences in means of body measures and in frequency of obesity between the sexes and by level of retardation were tested for statistical significance by means of a
RESULTS The subjects appeared to be well-nourished, and only one had a record history of anaemia (unspecified type). Medical records indicated a high frequency of pulmonary tuberculosis (thirty-two cases), but the disease had been arrested in all cases. Epilepsy was reported in eighty (46.8 per cent) of the subjects. Cardiovascular diseases were infrequently reported—i.e., hypertension (three cases), myocardial infarction (one case), heart murmur and aortic stenosis (two cases), and unspecified "cardiovascular disease" (one case). Respiratory diseases included emphysema (seven cases, or 4-1 per cent), bronchitis (two cases), pnetimonia (two cases), and pleurisy (one case). Other selected conditions reported in medical histories included: diabetes mellitus (two cases), arthritis (three cases), gallbladder disease (one case) and appendicitis (one case). Obesity was reported in the medical records of twenty of the 161 subjects (11.7 per cent). Mean body measurements, by level of retardation and sex, are shown in Tables 1 and 2. In males, the moderately retarded had a greater mean triceps skinfold relative to the mildly and severely retarded. A similar pattern is shown among the females. None of the differences in mean body measures, however, is statistically significant for these small samples defined by level of retardation. The percentage of obesity by age and sex is shown in Table 3. The frequency of obesity was slightly higher in males than in females when all age groups were combined (i.e., 20.4 per cent vs. 17.0 per cent). The age-pattern in the frequency of obesity.
A. P. POLEDNAK and JAN AULIFFE
11
Table 1 Body measurements of male retarded adults*
Mild {N=36) Mean S.D.
Level of retardation Moderate{N=41) Severe {N=3]) Mean S.D. Mean S.D.
Total {N=108) Mean S.D.
165.9 68.5 280.9
12.0 35.5
167.6 70.0 284.0
11.2 15.4 41.8
167.6 70.0 290.1
8.6 11.4 34.8
167.4 69.5 285.1
13.1 37.6
13.1 41.6
8.9 14.6
15.0 39.6
10.2 13.1
13.5 38.6
7.5 9.9
13.9 39.9
12.7
Variable Height (cm.) Weight (kg.) Arm girth (mm.) Triceps Skinfold (mm.) Age (yrs.)
8.1
9.4
9.0
*None of the differences in body measurement between the three groups (mild, moderate and severe) is statistically significant.
Table 2 Body measurements offemale retarded adults*
Mild (7V= 75) Mean S.D.
Level of retardation Moderate {N= i 21] Severe(JV=77) Mean S.D. Mean S.D.
152.1 58.3 259.1
9.7 15.0 52.0
153.2 61.8 286.8
8.9 9.6 37.2
146.8 53.0 254.9
7.9 10.9 44.5
150.9 58.0 268.7
9.1 12.1 45.7
16.2 36.9
7.8 15.3
20.7 50.1
7.3 13.4
17.1 37.1
10.0 14.8
18.3 42.2
8.8 15.5
Variable Height (cm.) Weight (kg.) Arm girth (mm.) Triceps skinfold (mm.) Age (yrs.)
Total (.V=55 Mean S.D.
*Nonfc ofthe differences in body measurement between the three groups (mild, moderate and severe) is statistically significant.
Table 3 Frequency of obesity* by age and sex
Age
18-19 20-29 30-39 40-49 50-59 60TOTAL
Male No. of
/o
Total no.
obese
obese
Total no.
obese
2 29 14 33 26 4
0 7 3
1 15
0
7 0
0.0 24.1 21.4 15.1 26.9 0.0
108
22
20.4
53
5
Female No. of
7 9 15 6
1 0 2 4
2
•Based on obesity standards of Seltzer and Mayer (1965) using triceps skinfold.
0/
/o obese
0.0 6.7 0.0 22.2 26.7 33.3 17.0
12
OBESITY
however, appeared to differ between the sexes. In younger age groups ( < forty years) the frequency was higher in males than in females, while in older age groups ( > forty years) the reverse was true. The number of females subject was small, however, and this sample may not be very representative of the entire female population of this institution. As noted above, twenty persons had obesity mentioned in their medical record (twelve males and eight females). Of these twenty, eleven were defined as obese on the basis of triceps skinfold, using the American standards (Seltzer and Mayer, 1967). Of the remaining nine who did not meet these criteria, seven had a triceps skinfold of 18 mm. or greater. As Mayer (1968:33) observes, these criteria define "unmistakable obesity", but a physician may "consider some patients whose skinfolds are slightly below our cut-off" points to be too fat for their body builds". Apparently, this was the case for these seven patients. The frequency of obesity by level of retardation and sex is presented in Table 4. The moderately retarded showed the highest percentage of obesity, but none of the differences in percentage of obesity by level of retardation was statistically significant. Table 5 shows that use of the obesity standards of Seltzer and Mayer (1965) resulted in a clear discrimination of males in terms of means on body measures. Mean age and height did not differ significantly between obese and non obese males, but Table 4 Frequency of obesity by level of retardation and sex*
Level of retardation
Mild Moderate Severe TOTAL
Total no.
Males No. obese
obese
Total no.
36 41 31
6 12 4
16.7 29.3 12.9
15 21 17
2 4 3
13.3 19.0 17.6
108
22
20.4
53
9
17.0
/o
Females No. /o obese obese
Total no.
Total No. obese
obese
51 62 48
8 16 7
15.7 25.8 14.6
31
19.3
161
/o
*None of the differences in percentage of obesity is statistically significant.
Table 5 Body measurements of obese and non-obese males
Variable Age (yrs.) Height (cm.) ' Weight (kg.) Arm girth (mm.) Triceps skinfold (mm.)
Obese N=22) Mean S.D.
Non-obese {N= 86) Mean S.D.
39.3 168.9 85.7 332.7 29.0
40.1 166.9 65.3 272.9 10.1
13.1 8.6 10.2 24.0 4.0
12.7 9.7 10.3 30.1 4.9
Significance Difference p 0.8 2.0 20.4 59.8 18.9
n.s. n.s.
OBESITY IN AN INSTITUTIONALISED ADULT MENTALLY RETARDED POPULATION A. P. POLEDNAK* and JAN AULIFFE Birth Defects Institute, State Department of Health, Albany, New Tork
Since the institution may be the only living environment for many retarded persons, an important consideration is the extent to which that environment is conducive to optimal health. Obesity is one health-related variable that is recognised as a major problem in the United States and Canada. The importance of obesity as a risk factor in chronic diseases is well documented; associations with diabetes (Paffenfarger and Wing, 1973), hypertension (Florey and Acheson, 1969; Goldman, Varady and Franklin, 1972) and cardio-vascular disease (Gordon and Kannel, 1973) have been confirmed by recent studies. There are few published studies on the frequency of obesity in institutionalised mentally retarded populations. Cumming, Goulding, and Baggley (1971) reported weight, height and body fat (based on skinfold measures) among sixty-seven retarded schoolchildren in Winnipeg, Manitoba. Compared with deaf and visually handicapped boys, retarded boys aged from thirteen to seventeen were heavier and slightly fatter. Retarded girls of the same group were considerably heavier and fatter than the other two groups. Skinfold data were not presented in terms of accepted obesity standards. In Uppsala, Sweden, various anthropometric measures were reported among thirty-nine male and twenty-four female retarded persons aged nineteen to thirty-nine (Nordgren, 1970). For the males, skinfolds were significantly greater in the retarded group compared with an unspecified normal population. These limited data indicate the need for studies of larger groups, using established indices of obesity. SUBJECTS AND METHOD Subjects were mentally retarded residents at the Oxford Mental Health Centre, Woodstock, Ontario. This facility was formerly a tuberculosis centre, but now provides services only for the retarded. Subjects in the present study included all residents of Activity Unit "A", comprising 161 adults. The age range was eighteen to seventy-three years. The sample included 108 males (mean age 39.9 ± 12.7 S.D. years) and fifty-three females (mean age 42.2 ± 15.5 S.D. years). The level of retardation ofthe subjects was as follows: for males, thirty-six mild, forty-two moderate, and thirty-one severe; and for females, fifteen mild, twenty-one moderate, and seventeen severe. Specific syndromes of mental retardation reported included Down's syndrome (thirteen cases or 7.6 per cent), tuberous sclerosis (one case), and phenylketonuria (one case). Medical histories were obtained from individual record files. All diseases or conditions were noted, as recorded at the last annual medical examination. Obesity *Present address: Centre for Human Radiobiology, Argonne National Laboratory, Argonne, Illinois 60439. Received 16th September, 1975
9
10
OBESITY
was also noted when it appeared on the medical record. These data should give a general indication of the health and nutritional status of the subjects. Triceps skinfold, upper arm circumference, height and weight were measured. Height was measured with the subject standing against a wall without shoes, and recorded to the nearest half-inch. Triceps skinfold was measured on the bare right arm, using a Harpenden caliper. Arm circumference was measured on the bare right arm, using a flexible steel tape. Weight was measured on a spring scale with subject wearing light indoor clothing. The best criteria for obesity involve skinfold measurements at selected sites (Mayer, 1968; Seltzer and Mayer, 1965, 1967; Seltzer, Stoudt, Bell and Mayer, 1970). Obesity standards based on triceps skinfold (Seltzer and Mayer, 1965) have been recommended for large field surveys and clinical work (U.S. Public Health, 1966), and have been used in the present study. These standards were derived from extensive data on the distribution of skinfolds in the American population. Arbitrary cut-ofT points were defined as triceps skinfold greater than the population mean by more than one standard deviation (Seltzer and Mayer, 1965). It should be noted that the triceps skinfold criteria are useful for screening purposes, but the obesity defined is not necessarily severe in clinical terms or in relation to risk of specific diseases. Differences in means of body measures and in frequency of obesity between the sexes and by level of retardation were tested for statistical significance by means of a
RESULTS The subjects appeared to be well-nourished, and only one had a record history of anaemia (unspecified type). Medical records indicated a high frequency of pulmonary tuberculosis (thirty-two cases), but the disease had been arrested in all cases. Epilepsy was reported in eighty (46.8 per cent) of the subjects. Cardiovascular diseases were infrequently reported—i.e., hypertension (three cases), myocardial infarction (one case), heart murmur and aortic stenosis (two cases), and unspecified "cardiovascular disease" (one case). Respiratory diseases included emphysema (seven cases, or 4-1 per cent), bronchitis (two cases), pnetimonia (two cases), and pleurisy (one case). Other selected conditions reported in medical histories included: diabetes mellitus (two cases), arthritis (three cases), gallbladder disease (one case) and appendicitis (one case). Obesity was reported in the medical records of twenty of the 161 subjects (11.7 per cent). Mean body measurements, by level of retardation and sex, are shown in Tables 1 and 2. In males, the moderately retarded had a greater mean triceps skinfold relative to the mildly and severely retarded. A similar pattern is shown among the females. None of the differences in mean body measures, however, is statistically significant for these small samples defined by level of retardation. The percentage of obesity by age and sex is shown in Table 3. The frequency of obesity was slightly higher in males than in females when all age groups were combined (i.e., 20.4 per cent vs. 17.0 per cent). The age-pattern in the frequency of obesity.
A. P. POLEDNAK and JAN AULIFFE
11
Table 1 Body measurements of male retarded adults*
Mild {N=36) Mean S.D.
Level of retardation Moderate{N=41) Severe {N=3]) Mean S.D. Mean S.D.
Total {N=108) Mean S.D.
165.9 68.5 280.9
12.0 35.5
167.6 70.0 284.0
11.2 15.4 41.8
167.6 70.0 290.1
8.6 11.4 34.8
167.4 69.5 285.1
13.1 37.6
13.1 41.6
8.9 14.6
15.0 39.6
10.2 13.1
13.5 38.6
7.5 9.9
13.9 39.9
12.7
Variable Height (cm.) Weight (kg.) Arm girth (mm.) Triceps Skinfold (mm.) Age (yrs.)
8.1
9.4
9.0
*None of the differences in body measurement between the three groups (mild, moderate and severe) is statistically significant.
Table 2 Body measurements offemale retarded adults*
Mild (7V= 75) Mean S.D.
Level of retardation Moderate {N= i 21] Severe(JV=77) Mean S.D. Mean S.D.
152.1 58.3 259.1
9.7 15.0 52.0
153.2 61.8 286.8
8.9 9.6 37.2
146.8 53.0 254.9
7.9 10.9 44.5
150.9 58.0 268.7
9.1 12.1 45.7
16.2 36.9
7.8 15.3
20.7 50.1
7.3 13.4
17.1 37.1
10.0 14.8
18.3 42.2
8.8 15.5
Variable Height (cm.) Weight (kg.) Arm girth (mm.) Triceps skinfold (mm.) Age (yrs.)
Total (.V=55 Mean S.D.
*Nonfc ofthe differences in body measurement between the three groups (mild, moderate and severe) is statistically significant.
Table 3 Frequency of obesity* by age and sex
Age
18-19 20-29 30-39 40-49 50-59 60TOTAL
Male No. of
/o
Total no.
obese
obese
Total no.
obese
2 29 14 33 26 4
0 7 3
1 15
0
7 0
0.0 24.1 21.4 15.1 26.9 0.0
108
22
20.4
53
5
Female No. of
7 9 15 6
1 0 2 4
2
•Based on obesity standards of Seltzer and Mayer (1965) using triceps skinfold.
0/
/o obese
0.0 6.7 0.0 22.2 26.7 33.3 17.0
12
OBESITY
however, appeared to differ between the sexes. In younger age groups ( < forty years) the frequency was higher in males than in females, while in older age groups ( > forty years) the reverse was true. The number of females subject was small, however, and this sample may not be very representative of the entire female population of this institution. As noted above, twenty persons had obesity mentioned in their medical record (twelve males and eight females). Of these twenty, eleven were defined as obese on the basis of triceps skinfold, using the American standards (Seltzer and Mayer, 1967). Of the remaining nine who did not meet these criteria, seven had a triceps skinfold of 18 mm. or greater. As Mayer (1968:33) observes, these criteria define "unmistakable obesity", but a physician may "consider some patients whose skinfolds are slightly below our cut-off" points to be too fat for their body builds". Apparently, this was the case for these seven patients. The frequency of obesity by level of retardation and sex is presented in Table 4. The moderately retarded showed the highest percentage of obesity, but none of the differences in percentage of obesity by level of retardation was statistically significant. Table 5 shows that use of the obesity standards of Seltzer and Mayer (1965) resulted in a clear discrimination of males in terms of means on body measures. Mean age and height did not differ significantly between obese and non obese males, but Table 4 Frequency of obesity by level of retardation and sex*
Level of retardation
Mild Moderate Severe TOTAL
Total no.
Males No. obese
obese
Total no.
36 41 31
6 12 4
16.7 29.3 12.9
15 21 17
2 4 3
13.3 19.0 17.6
108
22
20.4
53
9
17.0
/o
Females No. /o obese obese
Total no.
Total No. obese
obese
51 62 48
8 16 7
15.7 25.8 14.6
31
19.3
161
/o
*None of the differences in percentage of obesity is statistically significant.
Table 5 Body measurements of obese and non-obese males
Variable Age (yrs.) Height (cm.) ' Weight (kg.) Arm girth (mm.) Triceps skinfold (mm.)
Obese N=22) Mean S.D.
Non-obese {N= 86) Mean S.D.
39.3 168.9 85.7 332.7 29.0
40.1 166.9 65.3 272.9 10.1
13.1 8.6 10.2 24.0 4.0
12.7 9.7 10.3 30.1 4.9
Significance Difference p 0.8 2.0 20.4 59.8 18.9
n.s. n.s.
