Body mass index and prostate specific antigen levels in Jamaican men.

OBJECTIVE: To investigate the relationship between body mass index (BMI) and prostate specific antigen (PSA) levels in Jamaican men. METHODS: Men, 40-79 years old, attending public and private urology clinics in Kingston, Jamaica were recruited to a case-control study on the role of dietary and lifestyle factors on prostate cancer. Trained interviewers administered questionnaires and measured weight and height using standardized techniques. Blood samples for PSA were measured at a central laboratory using a micro-particle enzyme immunoassay method. Prostate biopsy was used to confirm prostate cancer. Multivariable linear regression was used to examine the relationship between BMI and PSA separately in the cases and controls. RESULTS: Data from 501 men (233 cases and 263 controls) were assessed. Thirty-five per cent of subjects were overweight and 13% were obese. Among cases, the median PSA was 35.3 ng/dL in normal weight, 26.1 ng/dL in overweight and 14.5 ng/dL in obese men (p = 0.02). For controls, median PSA was 2.0 ng/dL in normal weight, 1.3 ng/dL in overweight and 1.1ng/dl in obese men (p = 0.01). Among cases, BMI was negatively associated with PSA (B(SE) per 5 kg/m2 (BMI difference = -0.51 (0.13); p < 0.01) and remained significant after adjustment for age, sexual activity, smoking, use of statins and tumour grade. For controls, the BMI was also inversely related to the PSA (B(SE) per 5 kg/m2 difference -0.17 (0.07)) but the effect became of borderline significance after adjusting for age. CONCLUSIONS: Prostate specific antigen was inversely related to body mass index in Jamaican men with prostate cancer. Clinicians should consider this association when interpreting PSA results.

Cold-induced elevation of forearm vascular resistance is inversely related to birth weight.

Fetal growth retardation has been linked to elevated blood pressure in adult life. This association between birth weight and blood pressure is present in childhood and is amplified with age. However, the mechanisms that underlie this association are largely unknown. We examined the relationship between birth weight and forearm vascular resistance and forearm blood flow in children aged 9-12.7 years. A total of 58 children were randomly selected from a cohort of 1610 born at the University Hospital of the West Indies in Jamaica where adequate antenatal and delivery records were available. Blood pressure, heart rate and forearm blood flow (by venous occlusion plethysmography) were measured at rest and after cold pressor and mental arithmetic tests. There was a significant inverse correlation between birth weight and the change in the vascular resistance for the cold pressor test (r=-0.47; P<0.001) and the mental arithmetic stress test (r=-0.26; P=0.05). The log ratio of vascular resistance under stress to resting decreased by 0.289 units per kg of birth weight (95% CI: 0.145-0.434; P=0.0002). Lower birth weight is associated with increased vascular responsiveness. Increased vascular resistance might be one mechanism linking fetal growth to subsequent elevated blood pressure.

Energetic determinants of glucose tolerance status in Jamaican adults.

As type 2 diabetes mellitus (DM2), obesity and sedentary lifestyles are increasing in developing countries, this observational study investigated the role of physical activity on DM2 in Jamaica. Anthropometry, body composition (by bioelectrical impedance analysis) and glucose tolerance status was assessed in 722 adults in 1993 and 1997. Energy expenditure was estimated in a subset using measured resting energy expenditure in combination with self-reported activity recalls. The rates of impaired glucose tolerance (IGT) were 23.7 and 27.3%, and DM2 were 16.3 and 23.7% among men and women, respectively. After adjusting for body composition, a one-unit increase in physical activity significantly reduced the odds of having diabetes (OR = 0.05; 95% CI: 0.004, 0.66), but not IGT. Hence, decreased physical activity is a significant independent contributor to the high rates of glucose intolerance in Jamaica. Efforts must be directed at minimizing obesity and increasing physical activity in developing countries.

Features of isolated post-challenge hyperglycaemia in Jamaican adults.

Isolated post-challenge hyperglycaemia (IPH) can be defined as a two-hour plasma glucose concentration > or = 11.1 mmol/L with a fasting plasma glucose concentration < 7.0 mmol/L. The aim of this prospective study was to determine the prevalence of IPH in a cohort of Jamaican individuals, and to determine if simple clinical features may predict the presence and subsequent diagnosis of IPH. A cohort of 1694 adults aged 25-74 years without physician-diagnosed diabetes mellitus was randomly selected. An oral glucose tolerance test (OGTT) was performed. Anthropometry, blood pressure and lipid profiles were measured. The prevalence of undiagnosed diabetes mellitus by the 1999 World Health Organization criteria was 6.4%. IPH accounted for 24% of these cases and 1.4% of the entire population. Individuals with IPH were significantly older, with greater body mass index, waist-hip ratio, systolic blood pressure, fasting blood glucose, total cholesterol and LDL-cholesterol than individuals with normal glucose tolerance. Individuals with IPH were not significantly different from individuals with fasting plasma glucose levels > or = 7 mmol/L (i.e. fasting hyperglycaemia) in anthropometry or blood pressure. However, total cholesterol and LDL-C were significantly elevated in the IPH group. OGTT screening of individuals with impaired fasting glucose (i.e. 6.1-6.9 mmol/l) could reduce the IPH group by 50%. Reducing the threshold for fasting glucose to 5.6 mmol/L would correctly classify 87% of the population. We concluded that individuals with IPH have features of the metabolic syndrome, which can aid in selection for screening. OGTT screening of individuals with fasting glucose values of 5.6-6.9 mmol/l is needed to identify IPH.

Features of isolated post-challenge hyperglycaemia in Jamaican adults

Isolated post-challenge hyperglycaemia (IPH) can be defined as a two-hour plasma glucose concentration > or = 11.1 mmol/L with a fasting plasma glucose concentration < 7.0 mmol/L. The aim of this prospective study was to determine the prevalence of IPH in a cohort of Jamaican individuals, and to determine if simple clinical features may predict the presence and subsequent diagnosis of IPH. A cohort of 1694 adults aged 25-74 years without physician-diagnosed diabetes mellitus was randomly selected. An oral glucose tolerance test (OGTT) was performed. Anthropometry, blood pressure and lipid profiles were measured. The prevalence of undiagnosed diabetes mellitus by the 1999 World Health Organization criteria was 6.4. IPH accounted for 24 of these cases and 1.4 of the entire population. Individuals with IPH were significantly older, with greater body mass index, waist-hip ratio, systolic blood pressure, fasting blood glucose, total cholesterol and LDL-cholesterol than individuals with normal glucose tolerance. Individuals with IPH were not significantly different from individuals with fasting plasma glucose levels > or = 7 mmol/L (i.e. fasting hyperglycaemia) in anthropometry or blood pressure. However, total cholesterol and LDL-C were significantly elevated in the IPH group. OGTT screening of individuals with impaired fasting glucose (i.e. 6.1-6.9 mmol/l) could reduce the IPH group by 50. Reducing the threshold for fasting glucose to 5.6 mmol/L would correctly classify 87 of the population. We concluded that individuals with IPH have features of the metabolic syndrome, which can aid in selection for screening. OGTT screening of individuals with fasting glucose values of 5.6-6.9 mmol/l is needed to identify IPH

Fasting levels of serum glucose, cholesterol and triglyceride at age eleven to twelve years in stunted and non-stunted Jamaican children.

AIM: To determine whether fasting serum concentrations of glucose, cholesterol and triglyceride at age 11-12 y (a) differed between children stunted in early childhood and those who were never stunted, (b) were related to birthweight or current anthropometry and (c) were related to stunting after controlling for current size. METHODS: Anthropometry, serum glucose and lipid concentrations were measured in 112 children stunted in early childhood and 181 non-stunted children. RESULTS: Children who were stunted in infancy remained shorter, weighed less and were significantly less fat than non-stunted children but had a more central distribution of fat. They were also less likely to have entered puberty. Non-stunted children had higher fasting serum triglyceride concentrations than stunted children (p < 0.05). There were no significant correlations between birthweight and fasting glucose or any measure of serum lipids. The percentage of variance in biochemical measures explained by anthropometry was low: between 2.1 for HDL cholesterol and 14.6 for triglyceride. Nutritional status in early childhood (stunted or non-stunted) made no additional contribution to the variance. CONCLUSIONS: Linear growth retardation in early childhood was not independently related to fasting serum concentrations of glucose, cholesterol and triglyceride at age 11-12 y. However, despite being thinner, stunted children had a more central distribution of fat.

Second-trimester placental volume and infant size at birth.

OBJECTIVE: To investigate the ability of second-trimester placental volume measured sonographically to predict birth size. METHODS: A total of 712 women were recruited from the antenatal clinic of the University Hospital of the West Indies; 561 fulfilled the study criteria and progressed to delivery. Placental volume and fetal anthropometry (biparietal diameter, head and abdominal circumferences, and femoral length) were measured sonographically at 14, 17, and 20 weeks. The main outcome measures were infant birth and placental weights, length, head, chest, and abdominal circumferences at birth. RESULTS: Placental volume in the second trimester was positively associated with all birth measurements. Of the fetal measurements at 14 and at 17 weeks, head circumference was the strongest predictor of birth weight (B [slope of the regression line] =.095, P =.014 at 14 weeks; B =.118, P =.012 at 17 weeks), but at 20 weeks, abdominal circumference was the strongest. However, at each age, placental volume was the strongest determinant of birth weight, and improved the prediction based only on fetal measurements. The odds ratio for low birth weight (under 2500 g) increased by 1.68 (95% confidence interval 1.05, 2.69, P = 0.03) for every standard deviation decrease in placental volume at 14 weeks' gestation. CONCLUSION: The present study suggests that low birth weight was often preceded by small placental volume in the second trimester. Placental volume may be a more reliable predictor of size at birth than fetal measurements, and may be useful in early identification of the fetus at risk in the perinatal period.

The effects of birth weight and postnatal linear growth retardation on blood pressure at age 11-12 years.

STUDY OBJECTIVE: To determine the effects of birth weight and linear growth retardation (stunting) in early childhood on blood pressure at age 11-12 years. DESIGN: Prospective cohort study. SETTING: Kingston, Jamaica. PARTICIPANTS: 112 stunted children (height for age < -2 SD of the NCHS references) and 189 non-stunted children (height for age > -1 SD), identified at age 9-24 months by a survey of poor neighbourhoods in Kingston. MAIN RESULTS: Current weight was the strongest predictor of systolic blood pressure (beta= 4.90 mm Hg/SD weight 95%CI 3.97, 5.83). Birth weight predicted systolic blood pressure (beta = -1.28 mm Hg/SD change in birth weight, 95% CI -2.17, -0.38) after adjustment for current weight. There was a significant negative interaction between stunting in early childhood and current weight indicating a larger effect of increased current weight in children who experienced linear growth retardation in early childhood. There was no interaction between birth weight and current weight. The increase in blood pressure from age 7 to age 11-12 was greater in children with higher weight at age 11-12 and less in children with higher birth weight and weight at age 7. CONCLUSIONS: Birth weight predicted systolic blood pressure in Jamaican children aged 11-12. Postnatal growth retardation may potentiate the relation between current weight and blood pressure. Greater weight gain between ages 7 and 11 was associated with a greater increase in systolic blood pressure. The relation between growth and later blood pressure is complex and has prenatal and postnatal components.

Blood pressure is related to placental volume and birth weight.

The objective of this study was to determine whether maternal nutrition and fetal and placental size program blood pressure. A longitudinal study linking the maternal anthropometric measurements of the first antenatal visit, ultrasound data of placental and fetal size, anthropometry at birth, and childhood growth and blood pressure was performed. The subjects were 428 women who attended the antenatal clinic at the University Hospital of the West Indies, Kingston, Jamaica, and their children, who were subsequently followed up. Systolic blood pressure at ages 1, 2, 2.5, 3, and 3.5 years was the main outcome measure. Pooling the data across ages, systolic blood pressure fell by 1.4 mm Hg for every 1-kg increase in birth weight (95% CI 0.2 to 2.7, P=0.02) and by 1.2 mm Hg for every 100-mL increase in placental volume at 20 weeks of gestation (95% CI 0.4 to 2.0, P=0.004). Blood pressure was also negatively associated with placental volume at 17 weeks and fetal abdominal circumference at 20 weeks. Measures of maternal nutritional status were strongly related to birth weight and placental volume but not directly to childhood blood pressure at these young ages. In conclusion, blood pressure is associated with fetal size in this population, as previously described among Europeans. We found associations between placental volume and abdominal circumference in the second trimester and childhood blood pressure, suggesting that the initiating events of blood pressure programming occur early in pregnancy. Measures of maternal nutritional status were not directly related to childhood blood pressure at these young ages but were strong predictors of both birth weight and placental volume, suggesting an indirect relation.

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% 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% 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 mass.

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 11.4of 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 2.6of 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 mass.

Glycine is not formed through the amino transferase reaction in human or rat placenta.

The fetus has a substantial demand for glycine, which is satisfied in part by placental formation. The ability to form glycine through the activity of alanine:glyoxylate aminotransferase enzyme was measured in placentae from normal term human pregnancies and placentae from rats at day 20 of gestation. There was no detectable enzyme activity in either human or rat placentae, although activity was measured in rat liver. It is concluded that in the placenta glycine is only formed from serine through the activity of serine hydroxymethyl transferase enzyme, which uses folate as a cofactor, because there are no other known metabolic pathways for endogenous glycine production.

Leptin and body composition of Nigerians, Jamaicans, and US blacks.

The role of leptin in humans remains controversial. Leptin concentrations are highly correlated with body fat stores. We tested whether or not this relation was consistent across the range of body composition encompassing the lean as well as the obese. Individuals participating in community-based comparative research in Nigeria (n = 363), Jamaica (n = 372), and the United States (Maywood, IL; n = 699) had their plasma leptin concentrations and body compositions (with bioelectrical impedance analysis) measured. All participants identified themselves as being black. Body mass index (in kg/m2) ranged from 14 to 62. Large differences in mean plasma leptin were noted across populations for both men and women in Nigeria, Jamaica, and the United States, respectively (men: 2.8, 3.9, and 6.8 microg/L; women: 10.3, 18.6, and 27.7 microg/L). An exponential function fit the relation between percentage body fat or total fat mass and leptin for men and women at each site. For women and men the exponential function with either percentage body fat or total fat mass was of the same shape, but increased by a constant in women, yielding higher leptin concentrations than in men at every level of body fat. On the basis of this broad distribution of body composition, the data suggest an exponential response of leptin to increases in body fat stores, consistent with the development of leptin resistance in individuals developing obesity. These findings likewise confirm that men and women exhibit different set points in terms of leptin production.

Leptin concentration in women is influenced by regional distribution of adipose tissue.

Leptin concentrations in humans are increased with obesity, and women have higher leptin concentrations than men. This sex difference reflects the greater fat mass of women. However, there is evidence that factors other than the size of the adipose tissue mass contribute to serum leptin concentrations. This study was undertaken to determine whether anthropometric factors influenced leptin concentrations in our population. Leptin concentrations were measured in 375 persons from a population study of hypertension and diabetes for whom body-composition data (bio-electrical impedance analysis and anthropometry) were available. Serum leptin concentrations were more than four times higher in women than in men (18.5 +/- 13.9 compared with 3.8 +/- 3.6 ng/L, P < 0.0001). In individuals with comparable body mass indexes, these differences persisted after adjustment for either percentage fat (P < 0.05) or fat mass (P < 0.0001) by multivariate-regression analysis. After fat mass was adjusted for, the serum leptin concentration in both men and women was independent of waist circumference but in women was associated with hip circumference. Hip circumference is a proxy measure of peripheral fat and these results suggest that the larger hips of women may contribute to the sex difference in serum leptin concentration.

The angiotensin converting enzyme and blood pressure in Jamaicans.

An insertion/deletion (I/D) polymorphism of the angiotensin I converting enzyme gene influences the level of serum angiotensin converting enzyme activity and has been associated with risk of several cardiovascular conditions. The relationship to blood pressure remains uncertain, however. We conducted a population-based survey in Kingston, Jamaica, to examine the association between angiotensin converting enzyme genotype, angiotensin converting enzyme serum activity and blood pressure. Serum angiotensin converting enzyme activity was measured and genotyping performed for the I/D polymorphism in 500 community residents. The overall prevalence of the D allele was 59.3%. Angiotensin converting enzyme genotype was not significantly related to blood pressure (P = .16), although it did influence angiotensin-converting enzyme activity, leading to an increase of 35% among individuals with the DD as compared with II genotype. Angiotensin converting enzyme levels were significantly higher in hypertensives as compared with normotensives (P < .05). A modest correlation was observed between blood pressure and angiotensin converting enzyme activity among untreated individuals (r = 0.11; P = .04), although this did not persist in multivariate analysis. A relationship between body mass index and angiotensin converting enzyme activity was identified in both men and women that was independent of genotype. These data demonstrate findings among blacks which are consistent with other studies and suggest a relationship between angiotensin converting enzyme genotype, and serum activity which is influenced by both genetic and environmental factors. The potential role of ACE on blood pressure control in the population remains uncertain.

Relationship between maternal nutritional status and infant's weight and body proportions at birth.

OBJECTIVES: To examine maternal nutritional status and its relationship to infant weight and body proportions. DESIGN: Retrospective study of births from January-December 1990. SETTING: University Hospital of the West Indies, Jamaica. SUBJECTS: Records for 2394 live, singleton births, between 200-305 d gestation. MAIN OUTCOME MEASURES: Birth weight, crown heel length, head circumference, ponderal index, head circumference:length ratio, placental weight, placental:birth weight ratio. RESULTS: Mothers who were lighter had babies who had lower birth weight, were shorter, had smaller heads and had a higher HC:L ratio. Shorter and thinner women had babies who had lower birth weights, were shorter, had smaller heads and lighter placentas. Thinner women also had babies with a lower placental:birth weight ratio, and their BMI's were not linearly related to ponderal index and HC:L ratio. Women whose first trimester Hb levels were < 9.5 g/dl had babies with the lowest birth weight, crown heel length, placental weight and ponderal index. These measurements increased as the Hb levels rose to 12.5 g/dl but then fell at Hb levels > 12.5 g/dl. In the second and third trimester Hb levels were negatively associated with birth weight, crown heel length, head circumference, placenta weight and ponderal index. CONCLUSIONS: The data support the hypothesis that poor maternal nutrition is associated with foetal growth restraint. Poor maternal nutrition as indicated by low weight, height, and BMI are associated with smaller, shorter babies with smaller heads. Haemoglobin levels > 12.5 g/dl in pregnancy are associated with lighter, shorter, thinner babies, with smaller heads.

ACE, angiotensinogen and obesity: a potential pathway leading to hypertension.

The renin-angiotensin system (RAS) plays a crucial role in the regulation of fluid volume, thereby influencing blood pressure (BP). Obesity is an important risk factor for hypertension, however the physiologic basis for this relationship has not been clarified. In a population survey we examined the potential relationship between the RAS and obesity. Based on community sampling, 449 individuals were recruited from metropolitan Kingston, Jamaica. Serum angiotensin-converting enzyme (ACE) and circulating angiotensinogen levels were measured and the associated genes were typed for previously described polymorphisms. Obese individuals (body mass index > 31) had significantly higher serum ACE and angiotensinogen levels, this relationship persisted for ACE in multivariate analyses controlling for BP, hypertension status, age, and gender. The insertion/deletion polymorphism of the ACE gene was associated with variation in the levels of ACE, but inconsistently with body mass index. Variants of the angiotensinogen gene leading to amino acid substitutions at positions 174 and 235 did not influence levels either of angiotensinogen or obesity. These data suggest that obesity may alter the levels of ACE and angiotensinogen, and provide a potential pathway through which obesity leads to elevation of BP.

Fetal growth and cardiovascular risk factors in Jamaican schoolchildren.

OBJECTIVE: To determine relation between schoolchildren's blood pressure, glycated haemoglobin level, and cholesterol concentration and their anthropometry, socioeconomic status, and birth measurements. DESIGN: Retrospective cohort study. SETTING: 27 schools closest to University Hospital of the West Indies, Kingston, Jamaica. SUBJECTS: 2337 children aged 6-16 years who were born at university hospital were recruited, and their birth records were recovered: 1610 had suitable records, 659 had records including birth length, and 610 of these were prepubertal. MAIN OUTCOME MEASURES: Blood pressure, glycated haemoglobin level, serum cholesterol concentration, anthropometry at birth, current anthropometry, and socioeconomic status. RESULTS: Multiple regression analysis showed that children's systolic blood pressure was inversely related to their birth weight (P < 0.0001) and directly related to their current weight. Glycated haemoglobin level was higher in children with thicker triceps skinfolds (P < 0.001) and who had been shorter at birth (P = 0.003). Serum cholesterol concentration was inversely related to current height (P = 0.001) and to length at birth (P = 0.09) and was directly related to triceps skinfold thickness and higher socioeconomic status (P < 0.001). CONCLUSIONS: Blood pressure in childhood was inversely related to birth weight and directly to current weight. Glycaemic control and serum cholesterol were related to short length at birth, height deficit in childhood, and childhood obesity.

Excessive excretion of 5-oxoproline and decreased levels of blood glutathione in type II diabetes mellitus.

Levels of blood glutathione (GSH) were measured in 26 type II diabetes mellitus patients compared to 36 controls. Total blood GSH did not differ significantly between the two groups (mean +/- s.d., 8.0 +/- 1.5 vs. 7.7 +/- 1.3 mmol/g Hb, respectively); however reduced GSH was lowered in diabetes mellitus (5.0 +/- 1.0 vs. 5.8 +/- 1.0 mmol/gHb; P = 0.01), whereas oxidized GSH was increased (0.4 +/- 0.2 vs. 0.2 +/- 0.1 mmol/gHb; P = 0.001). Urinary excretion of 5-oxoproline was excessive in the diabetic patients (14.5 +/- 9.9 vs. 3.8 +/- 1.4 mmol/24 h; P = 0.004), and was positively correlated with levels of glycosylated haemoglobin (r = 0.69; P less than 0.01).