A preliminary study of the indices of obesity among select group of apparently healthy Caribbean subjects

The purpose of this study was to assess the anthropometric indices of obesity among apparently healthy Caribbean subjects who have the potentials of living an affluent lifestyle. One hundred and eleven (38 males, 73 females) young adults aged between 17 and 38 years participated in the study. Subjects provided information on age, ethnic group, educational attainment, occupation, and previous record of body mass index (BMI) and family history of diabetes mellitus in a self-administered research questionnaire. Waist and hip circumferences (cm), weight (kg) and height (m) were measured. Subsequently, BMI and waist-to-hip ratio (W/H) were calculated. The majority of the subjects (83 percent) had never measured BMI. Although the male subjects were significantly taller and heavier than the females (p<0.01), there was no significant difference in the prevalence rates of obesity between the male and female subjects (p>0.05). In this preliminary study there was a trend for more females than males to be under weight (BMI< 20 kg/m2). The male subjects had significantly higher waist circumference than the females (p< 0.01), but both genders had a similar percentage of male and female subjects with increased waist circumference (p>0.05). The limitations of this study are its small size and self selection bias and hence the results obtained must be interpreted with caution. We suggest that assesment of body mass index should be incorporated in the routine clinical measurements of all patients to facilitate early identification, evaluation and treatment of overweight and obesity. (AU)

Obesity, hyperglycaemia and hyperinsulinaemia in Jamaica [abstract]

Insulin resistance (IR), with its associated with higher circulating levels of insulin and glucose occurs in non-insulin-dependent diabetes (NIDDM) and obesity and is often present in hypertension (HTN). The prevalence of these diseases is high in Jamaica and this study sought to determine the relationship between several measures of obesity, hyperinsulinaemia and hyperglycaemia. Anthropometric and glycaemic status variables were assessed in 469 men and 704 women. Fasting C-peptide and insulin levels were measured in subjects from the top and bottom 15 percent of a Body Mass Index (BMI) frequency distribution curve. The glucose/insulin ratio (Glu/Ins) was used as a measure of IR and the C-peptide/insulin as a measure of hepatic extraction. The obese (BMI> 32kg/m2) group had higher levels of fasting (Fglu) and postchallenge (2hGlu) glucose, insulin, C-peptide and lower Glu/Ins than the thin group (BMI<20kg/m2), suggesting greater IR. Forty-six percent of the obese were hyperinsulinaemic compared to 25 percent of the thin. Obese normogloglycaemics had higher levels of Fglu and 2hGlu than the thin normoglycaemics. Levels of glucose and insulin correlated with waist-hip ratio (WHR), waist and conicity measurements but not with BMI in the obese. In the thin group, there was correlation between glucose levels and WHR, Hyperglycaemia was more common in women. The higher levels of Fglu and 2hGlu in obese normoglycaemics suggest that the mechanisms responsible for the association between obesity and hyperglycaemia may already be operating. The association between hyperglycaemia, WHR and conicity but no BMI, suggests that `central tendency' may be a more useful indicator of dysglycaemia. The higher levels of hepatic extraction in the obese group indicate that the observed hyperinsulinaemia is not due to low hepatic extraction. (AU)

Desirable body size associated factors in Trinidadian adolescents

OBJECTIVES: To determine body size considered desirable by adolescents in Trinidad and to identify factors associated with it. DESIGN AND METHODS: A random sample of 1,139 adolescents, aged 14-17 years and attending secondary schools in Trinidad were selected for the study. Silhouettes of different body sizes were used to determine what was considered desirable body size. Weights and heights were measured to determine actual body size. RESULTS: 1,090 (96 percent) students participated, 512 males and 578 females. The calculated BMI indicated that 15 percent were underweight, 73 percent were normal and 13 percent were overweight. There was a significant gender difference in desirable body size (p<0.001). The majority of females (83 percent) wanted to be normal while 13 percent wanted to be underweight. In contrast, 66 percent of males wanted to be normal and 31 percent overweight. In males, sports personalities (55 percent) and movie stars (31 percent) were most important in influencing desirable body size while movie stars (44 percent) and fashion models (43 percent) were most important for females. There was no association between actual and desirable body size in females but the association was significant in males (p=0.004). More overweight males chose the overweight figure (45 percent) compared with normal (31 percent) or underweight (23 percent) males. Although 41 percent of adolescents said that they would like to remain the same size, more females (37 percent) than males (20 percent) said that they wanted to lose weight while more males (38 percent) than females (3 percent) wanted to gain weight (p<0.001). CONCLUSION: It is important that appropriate intervention be implemented to address this desire by adolescent males to be overweight.(Au)

Blood pressure in Jamaican children: relationship to body size and composition

Blood pressure levels in adults and children are related to body size and composition, but some of these relationships are unclear and they have been incompletely described in the Jamaican population. In a cross-sectional survey of 2,332 school children (6-16 years old; 1,046 boys, 1,286 girls), we measured systolic and diastolic blood pressure and pulse rate, and explored their relationship to weight, height, and waist, hip and mid-upper arm circumferences. The effect of these and other derived measures of body composition on blood pressure was explored in univariate and multivariate analysis. Blood pressure increased with age in both boys and girls, although the increase was greater for systolic than for diastolic blood pressure. The increase of systolic blood pressure among boys continued after age 11 years, but that for girls levelled off. Height and weight were the major predictors of blood pressure, but were highly correlated with each other and with all measures of body composition. Age, height and height-sex interaction explained 11.4 percent of systolic blood pressure variation, and the largest incremental contribution to this model was provided by the addition of body mass index or hip circumference, each explaining an additional 2.6 percent of the variance. Lean body mass made a larger contribution to blood pressure than percent fatness. Blood pressure in Jamaican children rises with age and this rise may be steeper in boys than girls. Blood pressure variation is significantly related to several measures of body composition including measures of fatness and fat free masses.(AU)

Microalbuminuria, renal function and waist: hip ratio in black hypertensive Jamaicans

OBJECTIVE: To investigate the relationship between blood pressure (BP), renal haemodynamics, anthropometric measures of obesity and urinary albumin excretion in hypertension and in a control group. METHODS: Urinary albumin, BP and anthropometric measurements were carried out in patients attending hypertension clinic of the University Hospital of the West Indies. A randomised stratified sample was then selected for renal haemodynamic assessment. A normoalbuminuric control group without hypertension or diabetes was also selected. Renal haemodynamics was assess by measured glomerular filtration rate using 51-chromium edetic acid (51 Cr-EDTA) and renal blood flow using 125-iodohippurate (125-PAH). RESULTS: Urinary albumium excretion was postively and significantly correlated with systolic pressure (B = 0.011, P < 0.003, R = 0.22), current body weight (B = 0.014, P < 0.04, R = 0.15) and the pressure of diabetes (B = 0.9, P < 0.001, R = 0.3). In the sample selected for renal haemodynamics, patients with microalbuminuria had lower age-adjusted corrected renal blood flow (P < 0.006), effective renal plasma flow (P < 0.006) when compared with patients without microalbuminuria was not different from those without. Urinary albumin excretion was postively and significantly correlated with systolic pressure (B = 0.016, P < 0.003, R = 0.40) and inversely related to corrected renal flow (B = -1.13, P < 0.0002, R = 0.46) Waist: hip ratio was inversely related to corrected renal blood flow (B = -1.74, P < 0.02, adjusted R = 0.48). CONCLUSION: Systolic BP, diabetes and body weight were significant predictors of albuminuria in our patients. Microalbuminuria and body fat distribution as assessed by waist: hip ratio were important determinants of renal haemodynamics in this population.(AU)

Insulin sensitivity in Jamaicans with hyperglycaemia (IGT and NIDDM) - abstract

Non-insulin dependent diabetes (NIDDM) is one of the major causes of morbidity and mortality in Jamaica. The relative contributions of insulin resistance (IR) and B-cell dysfunction (percent b-cell) in the aetiology of NIDDM are unknown. We looked at three indices of insulin sensitivity: (1) the fasting insulin/glucose ratio (IGR); and (2) IR and (3) percent B-cell in Jamaicans with hyperglycaemia. (2) and (3) were calculated using the HOMA model. Subjects were selected from the lowest and highest 15 percent of a post challenge 2 h glucose distribution. The IGR distribution of the normoglycaemic group was used to establish a normal range. IGR correlated well with IR (r = 0.89) and with percent B-cell (r = 0.60). 46.7 percent of the hyperglycaemic subjects had a low IGR suggesting impaired insulin production; 31.4 percent had high IGR indicating hyperinsulinaemia and insulin resistance. The remaining 22.9 percent was probably due to a mixture of both.(AU)

The age-prevalence profile of abdominal obesity among patients in a diabetes referral clinic in Jamaica

Generalised obesity is a major risk factor for cardiovascular disease, diabetes, hypertension and premature death, but abdominal or central obesity is even more closely related to these. Diabetes causes accelerated atherosclerosis and this results in peripheral vascular and ischaemic heart disease and stroke, major causes of death in diabetics in the Caribbean. Diabetics who have abdominal obesity are therefore at increased risk for these events. 485 patients attending the Diabetes Referral Clinic at the University Hospital of the West Indies, Jamaica, were evaluated for abdominal obesity based ont the ratio between their waist and hip measurements. There was an increase in the numbers of diabetics with increasing age. Abdominal obesity was significantly more prevalent among females (90 percent) than among males (34.9 percent) (X = 142; p < 0.0001), and massive obesity was detected in 31.1 percent of females. However, the prevalence of obesity among males and females was not significantly age-related. Given the high prevalence of obesity in this clinic population, more precise studies of abdominal obesity associated morbidity in diabetics should be undertaken.(AU)

Prevelance of NIDDM among populations of the African diaspora

OBJECTIVES: Rates of non-insulin-dependent diabetes mellitus have risen sharply in recent years among blacks in the U.S. and the U.K. Increase in risk have likewise been observed in the island nations of the Caribbean and in urban West Africa. To date, however, no systematic comparison of the geographic variation of NIDDM among black populations have been undertaken. RESEARCH DESIGN AND METHODS: In the course of an international collaborative study on cardiovascular disease, we used a standardized protocol to determine the rates of NIDDM and associated risk factors in populations of the African diaspora. Representative samples were drawn from sites in Nigeria, St. Lucia, Barbados, Jamaica, the United States, and the United Kingdom. A total of 4,823 individuals aged 25-74 years were recruited, all sites combined. RESULTS: In sharp contrast to a prevalence of 2 percent in Nigeria, age-adjusted prevalences of self-reported NIDDM were 9 percent in the Caribbean and 11 percent in the U.S. and the U.K. Mean BMI ranged from 22 kg/m2 among men in West Africa to 31 kg/m2 in women in the U.S. Disease prevalence across sites was essentially collinear with obesity, pointing to site differences in the balance between energy intake and expenditure as the primary determinant of differential NIDDM risk among these populations. CONCLUSIONS: In ethnic groups sharing a common genetic ancestry, these comparative data demonstrate the determing influence of changes in living conditions on the population risk of NIDDM.(AU)

Nutrition in early life - "long term effects" - Keynote Address

Most estimates indicate that during the next 20 years most of the morbidity and mortality in the world will be related to chronic diseases, such as cardiovascular disease, diabetes mellitus, some cancers and mental health. The aetiology of each condition is complex and multifactorial, but recent evidence shows that nutritional exposure during early life might be critical in determining individual susceptibility to a range of other environmental factors in the generation of chronic disease in adulthood. It is proposed that the underlying susceptibility originates through "programming" during fetal and early infant life. Thus, in response to a limited availability of nutrients the fetus adapts and this adaption results in a permanent change in organ structure and metabolic function, giving rise to the hypothesis of "Fetal Origins of Adult Disease". Across Britain there is a two-fold variation in cardiovascular disease which cannot be adequately explained by variations in lifestyle. Early studies suggested they may be explained by differences in the physique and growth of young women, the growth of their babies in utero and during infancy, and the consequent lifelong differences in the physiology and metabolism of the offspring. Novel epidemiological studies by Barker and colleagues in Southampton allowed exploration of these ideas using detailed maternity and health visitors records which have been kept from the early years of this century. Babies born fifty years ago were traced and their size at birth and one year of age related to the occurrence of cardiovascular disease in later life. Amongst 10,000 men in Hertfordshire who had lower birthweight and remained lighter than average at one year of age the risk of death from heart disease was three times that of men at the upper end of normal. Small size at birth is also associated with high blood pressure and diabetes, high serum cholesterol and disordered blood coagulation. The lightest babies at birth were ten times more likely to develop the metabolic syndrome of hypertension, impaired glucose tolerance and raised blood lipid levels than those who were heaviest at birth. Stroke is also increased in those with a lower birth weight. These relationships are even more evident in babies in whom growth is disproportionate, thus thinner babies are more likely to develop non-insulin diabetes mellitus as adults.(Au) [truncated at 2500 characters]

Microalbuminuria and renal function in primary hypertension and in diabetic hypertensives - abstract

The relationship between renal haemodynamics, measures of regional fat distribution (subscapular/triceps ratio, STR, and waist/hip ratio, WHR) and microalbuminuria (urinary albumin excretion < 300mg/l but > 30 mg/l) in patients with essential hypertension and hypertension with diabetes is unclear. Renal haemodynamic and anthropometric measurements were done on 72 hypertensive patients. Of these, 15 were in group 1, essential hypertension with microalbuminuria; 21 in group 2, essential hypertension with normo-albuminuria; 20 in group 3, diabetic hypertensives with microalbuminuria and 16 in group 4, diabetic hypertensives with normoalbuminuria. Group 1 had significantly lower renal plasma flow (p<0,01), and increased renal vascular resistance (p<0.005), filtration fraction (p<0.05), systolic (p<0.005), disatolic (p<0.001) and mean blood pressure (p<0.001) when compared to group 2 patients. There were no significant differences in the renal haemodynamic patterns and blood pressure levels between groups 3 and 4 patients. There were also no significant differences in serum creatinine between the groups. Men had significantly higher WHR (p<0.019) and STR(p<0.000) than women. The diabetic hypertensives also had higher waist/hip ratios than essential hypertensives (group 4 vs group 2), (p<0.04). The waist/hip ratio was also found to be an independent negative determinant of renal blood flow (R2 = 0.17, p<000), but was unrelated to blood pressure levels. There were no differences in STR between the groups nor was there any correlation between STR and renal haemodynamic variables or blood pressure. Within the groups, however, the effect of sex on waist/hip and subscapular/triceps ratio was not significant. The results suggest that microalbuminuria hypertensive patients have more profound haemodynamic alteration than normoalbuminuric hypertensive patients with diabetes mellitus (AU)

The Tobago leg of the Intersalt Study: urine sodium, bloodpressure and body mass index correlations - abstract

Tobago is a participant in the INTERSALT study, a multicentre study of inter-relationships between salt intake, bloodpressure and other variables. In the period 1986-1987, in Tobago, a random sample of 200 men and women, 25 in each of 8 age/sex groups, were enrolled in the study. Systolic and diastolic bloodpressure levels were measured with a Hawksley random sphygmomanometer under defined conditions, a spot urine and 24-hr. urine collection were obtained and information was obtained on cardio-vascular risk factors (questionnaire), drug schedules and alcohol intake. Overall in the INTERSALT study of 52 centres in 32 countries, increase of systolic and diastolic bloodpressure with age was significantly related to the average sodium excretion. In addition, sodium excretion (positive), body mass index (positive), heavy alcohol intake (positive) and potassium excretion (negative) were significantly related to the bloodpressure of individuals. In Tobago, prevalence of raised bloodpressure was 18 per cent. Thirteen per cent of men were heavy drinkers (>300 ml alcohol per week), and an average body mass index of 27.0 (kg/m2) and sodium/potassium ratio 2.77 were recorded (men and women combined). The results indicate above optimal values of these variables in Tobago, and suggest the potential for appropriate lifestyle changes of high bloodpressure in Tobago (AU)

Intracellular sodium and potassium and their relationship to blood pressure and body size

In the present study twenty-seven hypertensive patients, thirty-five normotensives without familial hypertension and twelve normotensives with familial hypertension were studied cross-sectoinally with regard to their age, sex, body mass index and - most important of all - the electrolyte (sodium and potassium) composition of their red and white blood cells. The major aim of this study was to find out if there were differences between the above mentioned subject groups regarding the electrolyte composition (sodium and potassium) of their blood cells. Another aim of this study was to characterize, through multiple regression analysis, the relationship between blood pressure, body mass index, and cell sodium and potasssium. Higher RBC-Na and WBC-Na were observed in essential hypertensives and normotensives with familial hypertension versus normotensive controls without familial hypertension. Normotensives with familial hypertension had WBC-Na and RBC-Na that were not significantly different from those in essential hypertensives. RBC-K was not significantly different between normotensives with familial hypertension, normotensives without familial hypertension and essential hypertensives. WBC-K was not significantly different between normotensives with familial hypertension and essential hypertensives. Normotensives with familial hypertension had significantly higher WBC-K than normotensives without familial hypertension and essential hypertensives. Correlations that were significant in the combined normotensive-hypertensive group include: (i) The direct relationship between blood pressure (systolic, diastolic and mean) and RBC-Na and also WBC-Na. (ii) The inverse relationship between blood pressure (diastolic and mean) and RBC-K and WBC-K. (iii) The direct relationship between body mass index and WBC-Na and WBC-K. Correlations that were significant in the essential hypertensive group include: (i) The inverse relationship between blood pressure (diastolic and mean) and RBC-K and also WBC-K. (ii) The direct relationship between body mass index and WBC-Na. Most of these results are compatible with the hypothesis that sodium is involved in the pathogenesis of essential hypertension (AU)

A biocultural analysis of blood pressure variation among the Black Caribs and creoles of St. Vincent, West Indies

This present study is a biochemical examination of blood pressure variation among the Black Caribs and Creoles of St. Vincent, West Indies. In particular, it investigates the etiology of essential (primary) hypertension by examining both cultural and biological contributory components. Four asspects of Caribbean culture are examined: Marital status, family size

Quantitative aspects of electrocardiograms of adults in a Jamaican rural population

The values of selected measurements from scalar electrocardiograms of a representative Jamaican population are reported. The tracings were obtained from 1067 adults aged 35 to 64 years, just under 90 percent of 1200 men and women selected randomly from a defined community of a hilly inland rural area. The participants were mostly small farmers, and their womenfolk, and they were of African origin. Measurements included intervals, axes, and amplitudes and three indices of left heart involvement-Morris's index of left atrial disease, Estes' score for left ventricular hypertrophy, and the Sokolow-Lyon criteria. Their distributions are compared with data from similar epidemiological studies and provide values for an ethnic group for which there are few population-based reports. The striking feature of these tracings was the high proportion with evidence of left ventricular hypertrophy, particularly those of men. The relation between certain electrocardiographic characteristics and age, body built, arterial pressure, and heart rate was investigated by multiple regression analysis, and this showed that little of the variation of most electrocardiographic measurements were explained by these variables. (AU)

Blood pressure levels of Guyanese adults of African and Indian origin

Blood pressure and anthropometric measurements were recorded from 842 Guyanese men and women aged 35 to 54 years of African and Indian orgin living in a similar environment. Blood pressure was higher in Africans than Indians but analysis of covariance showed the differences became insignificant when indices of body bulk, excluding obesity, were taken into consideration. The ethnic difference in blood pressure could be explained by ethnic differences in body habitus (AU)

The arm circumference as a field index of protein-calorie malnutrition of early childhood (PCM)

Current methods of assessing the community prevalence of PCM are noted. Weight-for-age remains the most practical of these, but is limited by absence of documentary proof of age in children in much of the world. Evidence is presented from various parts of the Caribbean and Africa which suggests, that the arm circumference is a useful public health index of PCM and can be employed even when ages are not known accurately (AU)