Glutathione metabolism in type 2 diabetes and its relationship with microvascular complications and glycemia.

AIMS/HYPOTHESES: We hypothesized that there is decreased synthesis of glutathione (GSH) in type 2 diabetes (T2DM) especially in the presence of microvascular complications, and this is dependent on the degree of hyperglycemia. METHODS: In this case-control study, we recruited 16 patients with T2DM (7 without and 9 with microvascular complications), and 8 age- and sex-matched non-diabetic controls. We measured GSH synthesis rate using an infusion of [2H2]-glycine as isotopic tracer and collection of blood samples for liquid chromatography mass spectrometric analysis. RESULTS: Compared to the controls, T2DM patients had lower erythrocyte GSH concentrations (0.90 ± 0.42 vs. 0.35 ± 0.30 mmol/L; P = 0.001) and absolute synthesis rates (1.03 ± 0.55 vs. 0.50 ± 0.69 mmol/L/day; P = 0.01), but not fractional synthesis rates (114 ± 45 vs. 143 ± 82%/day; P = 0.07). The magnitudes of changes in patients with complications were greater for both GSH concentrations and absolute synthesis rates (P-values ≤ 0.01) compared to controls. There were no differences in GSH concentrations and synthesis rates between T2DM patients with and without complications (P-values > 0.1). Fasting glucose and HbA1c did not correlate with GSH concentration or synthesis rates (P-values > 0.17). CONCLUSIONS: Compared to non-diabetic controls, patients with T2DM have glutathione deficiency, especially if they have microvascular complications. This is probably due to reduced synthesis and increased irreversible utilization by non-glycemic mechanisms.

Effects of cholesterol, C-reactive protein, and interleukin-6 on prostate cancer risk in a population of African ancestry.

PURPOSE: To investigate the association between serum cholesterol and prostate cancer and whether any effect may be mediated through inflammatory markers. METHODS: Data from a case-control study of 40-80 years old Jamaican male patients (229 cases; 252 controls) were used. Cases had incident histologically-confirmed prostate cancer and controls were men with normal digital rectal examination and prostate-specific antigen (PSA) < 4 µg/L or free: total PSA > 0.15 obtained from the same clinic. Total and HDL cholesterol, interleukin-6 (IL-6), and C-reactive protein (CRP) were measured from a non-fasting sample. Multivariable logistic regression models were used to evaluate the associations between these factors and prostate cancer, adjusting for age, body mass index, waist circumference, family history of prostate cancer, diabetes, hypertension, use of cholesterol-lowering drugs, and smoking. RESULTS: Total cholesterol [Mean (cases, 4.71 ± 1.07; controls, 4.64 ± 1.07 mmol/L)], CRP [median (cases, 2.11; controls, 2.09 µg/ml)], and IL-6: [median (cases, 3.34; controls, 3.24 pg/ml)] did not differ by PCA status. Higher total cholesterol was associated with an increased risk of low-grade disease after adjusting for potential confounders [multivariable-adjusted OR (95% CI): tertile 2: 3.32(1.66, 6.45), tertile 3: 2.14(1.07, 4.32)]. Total cholesterol was unrelated to overall prostate cancer or high-grade disease. There was no significant association between HDL cholesterol or any of the inflammatory markers with prostate cancer. CONCLUSIONS: Increasing total cholesterol but not inflammatory markers were associated with low-grade prostate cancer in Caribbean men.

Both serum 25-hydroxyvitamin D and calcium levels may increase the risk of incident prostate cancer in Caribbean men of African ancestry.

Circulating 25-hydroxyvitamin D [25(OH)D] concentrations have been associated with both higher and lower risk of prostate cancer (PCa), whereas elevated levels of circulating calcium has been related to higher risks. However, there are few studies that account for effects of both calcium and 25(OH)D concentrations on incident PCa in a black population. We examined these relationships in a case-control study of men 40-80 years old with newly diagnosed, histologically confirmed PCa in Jamaica, a tropical country. Mean serum calcium concentrations was higher among cases (2.32 ± 0.19 mmol/L) than controls, (2.27 ± 0.30 mmol/L) (P = 0.023) however, there were no differences in 25(OH)D by cancer status (cases, 33.67 ± 12.71 ng/mL; controls (32.25 ± 12.59 ng/mL). Serum calcium was not correlated with 25(OH)D (partial correlation: r, 0.06; P = 0.287). Multivariable-adjusted models showed a positive linear relationship between PCa and serum calcium (OR, 1.12; CI, 1.00-1.25 per 0.1 nmol/L). Serum 25(OH)D concentration also showed a positive association with PCa (OR, 1.23; CI, 1.01-1.49 per 10 ng/mL). The odds of PCa in men with serum 25(OH)D tertile 2 was OR, 2.18; CI, 1.04-4.43 and OR, 2.47 CI, 1.20-4.90 for tertile 3 (P(trend) = 0.013). Dietary intakes of calcium showed no relationship with PCa. Despite the strong relationship between serum calcium and vitamin D the mechanism by which each affects prostate cancer risk in men of African ancestry needs additional investigation.

High-Sensitivity C-Reactive Protein is Related to Central Obesity and the Number of Metabolic Syndrome Components in Jamaican Young Adults.

BACKGROUND: High-sensitivity C-reactive protein (hsCRP) has been shown to predict cardiovascular disease (CVD) endpoints and is associated with CVD risk factors and the metabolic syndrome. This study evaluated the association between hsCRP and CVD risk factors among Afro-Caribbean young adults in Jamaica. METHODS: We conducted a cross-sectional analysis of data from the Jamaica 1986 Birth Cohort Study. Data were collected between 2005 and 2007 when participants were 18-20 years old. All participants completed an interviewer administered questionnaire and had anthropometric and blood pressure (BP) measurements performed. Fasting blood samples were collected for measurement of glucose, lipids, and hsCRP. Logistic regression models were used to identify factors independently associated with high hsCRP. RESULTS: Analyses included 342 men and 404 women with mean age 18.8 ± 0.6 years. Approximately 15% of the participants had high risk hsCRP (>3 mg/L), with a higher prevalence among women (20 vs. 9%; p < 0.001). The prevalence of elevated hsCRP increased with body mass index category, high waist circumference (WC), high triglycerides, low high density lipoprotein, and lower parental education among women, but only for high WC and lower parental education among men. In logistic regression models controlling for sex and parental education, high WC was associated with significantly higher odds of high hsCRP (OR 7.8, 95% CI 4.8-12.9, p < 0.001). In a similar model, high hsCRP was also associated with the number of metabolic syndrome components. Compared to participants with no metabolic syndrome component, having one metabolic syndrome component was associated with a twofold higher odds of high hsCRP (OR 2.2, 95% CI 1.3-3.8, p = 0.005), while having three components was associated with a 14-fold higher odds of high hsCRP (OR 13.5, 95% CI 2.4-76.0, p < 0.001). CONCLUSION: High hsCRP is common among Jamaican young adults and is strongly associated with central obesity and the number of metabolic syndrome components.

Complex interaction between serum folate levels and genetic polymorphisms in folate pathway genes: biomarkers of prostate cancer aggressiveness.

Little is known about the role of folate and polymorphisms associated with folate metabolism on prostate cancer risk in populations of African origin. We examined the relationship between serum folate and prostate cancer and whether any association was modified by genetic polymorphisms for folate metabolism. The study was case-control in design and consisted of 218 men 40-80 years old with newly diagnosed, histologically confirmed prostate cancer and 236 cancer-free men attending the same urology clinics in Jamaica, March 2005-July 2007. Serum folate was measured by an immunoassay method and genomic DNA evaluated for MTHR (C677T and A1298C), MTRR A66G, and MTR A2756G polymorphisms. Mean serum folate concentration was higher among cases (12.3 ± 4.1 nmol/L) than controls (9.7 ± 4.2 nmol/L). Serum folate concentration showed a positive association with prostate cancer (OR, 4.41; CI, 2.52-7.72 per 10 nmol/L) regardless of grade. No interactions were observed between genotype and folate concentration, but a weak gene effect was observed for MTHFR A1298C and low-grade prostate cancer. Larger studies to investigate the role of gene-gene/gene-diet interactions in Black men are needed.

Associations of whole-blood fatty acids and dietary intakes with prostate cancer in Jamaica.

OBJECTIVE: To investigate the association of whole-blood fatty acids and reported intakes of fats with risk of prostate cancer (PCa). DESIGN: Case-control study of 209 men 40-80 years old with newly diagnosed, histologically confirmed prostate cancer and 226 cancer-free men attending the same urology clinics. Whole-blood fatty acid composition (mol%) was measured by gas chromatography and diet assessed by food frequency questionnaire. RESULTS: High whole-blood oleic acid composition (tertile 3 vs. tertile 1: OR, 0.37; CI, 0.14-0.0.98) and moderate palmitic acid proportions (tertile 2: OR, 0.29; CI, 0.12-0.70) (tertile 3: OR, 0.53; CI, 0.19-1.54) were inversely related to risk of PCa, whereas men with high linolenic acid proportions were at increased likelihood of PCa (tertile 3 vs. tertile 1: OR, 2.06; 1.29-3.27). Blood myristic, stearic and palmitoleic acids were not associated with PCa. Higher intakes of dietary MUFA were inversely related to prostate cancer (tertile 3 vs. tertile 1: OR, 0.39; CI 0.16-0.92). The principal source of dietary MUFA was avocado intake. Dietary intakes of other fats were not associated with PCa. CONCLUSIONS: Whole-blood and dietary MUFA reduced the risk of prostate cancer. The association may be related to avocado intakes. High blood linolenic acid was directly related to prostate cancer. These associations warrant further investigation.

Use of a food frequency questionnaire to assess diets of Jamaican adults: validation and correlation with biomarkers.

BACKGROUND: Assessment of habitual diet is important in investigations of diet-disease relationships. Many epidemiological studies use the food frequency questionnaire (FFQ) to evaluate dietary intakes but few studies validate the instrument against biological markers. The aim of this study was to assess the validity and reproducibility of a previously validated 70-item food frequency questionnaire (FFQ) that was expanded to 120-items to assess diet-cancer relations. METHODS: Relative validity of the FFQ was assessed against twelve 24-hour recalls administered over 12 months in 70 subjects. The FFQ was repeated after one year (FFQ2) to assess reproducibility. The validity of the FFQ was evaluated by comparing nutrient and food group intakes from 24-hour recalls with the first and second FFQ. In addition, FFQ validity for cholesterol and folate were determined through correlation with biomarkers (serum cholesterol, serum folate and whole blood folate) in 159 control subjects participating in a case-control prostate cancer study. RESULTS: Compared to recalls the FFQ tended to overestimate energy and carbohydrate intakes but gave no differences in intake for protein and fat. Quartile agreement for energy-adjusted nutrient intakes between FFQ2 and recalls ranged from 31.8%-77.3% for the lowest quartile and 20.8%-81.0% in the highest quartile. Gross misclassification of nutrients was low with the exceptions of protein, vitamin E and retinol and weighted kappa values ranged from 0.33 to 0.64 for other nutrients. Validity correlations for energy-adjusted nutrients (excluding retinol) were moderate to high (0.38-0.86). Correlation coefficients between multiple recalls and FFQ1 ranged from 0.27 (fruits) to 0.55 (red meat); the second FFQ gave somewhat higher coefficients (0.30 to 0.61). Reproducibility correlations for the nutrients ranged from 0.50 to 0.84.Calibration of the FFQ with biochemical markers showed modest correlations with serum cholesterol (0.24), serum folate (0.25) and whole blood folate (0.33) adjusted for age, energy, body mass index and smoking. CONCLUSIONS: The expanded FFQ had good relative validity for estimating food group and nutrient intakes (except retinol and vitamin E) and was a reliable measure of habitual intake. Associations with biomarkers were comparable to other studies.

Urinary phytoestrogens and risk of prostate cancer in Jamaican men.

We evaluated the relationship of spot urinary concentrations of phytoestrogens with total prostate cancer and tumor grade in a hospital-based case-control study in Jamaica. Urine samples were analyzed for genistein, daidzein, equol (isoflavones), and enterolactone (lignan) among newly diagnosed cases (n = 175) and controls (n = 194). Urinary concentrations of enterolactone (lignan) were higher among cases. There were no significant differences in median concentrations of isoflavone excretion. Compared with non-producers of equol (reference tertile), men who produced equol were at decreased risk of total prostate cancer (tertile 2: OR, 0.42; CI, 0.23-0.75) (tertile 3: OR, 0.48; CI, 0.26-0.87) (p (trend), 0.020) and high-grade disease (tertile 2: OR, 0.31; CI, 0.15-0.61) (tertile 3: OR, 0.29; CI, 0.13-0.60) (p (trend), 0.001). Higher concentrations of enterolactone were positively related to total prostate cancer (OR, 1.85; CI, 1.01-3.44; p (trend), 0.027) as well as high-grade disease (OR, 2.46; CI, 1.11-5.46; p (trend), 0.023). There were no associations between urinary excretion of genistein and daidzein with risk of prostate cancer. Producers of equol (isoflavone) may be at reduced risk of total- and high-grade prostate cancer whereas enterolactone may increase the likelihood of disease.

Sex-differences in adiponectin levels and body fat distribution: longitudinal observations in Afro-Jamaicans.

We longitudinally explored the relationship of body size and adiponectin levels in 393 community-dwelling Afro-Jamaicans. Adiponectin levels were greater in women, increased with age and declined with abdominal adiposity. Multivariate regression analyses suggest that subcutaneous fat in women may contribute significantly to the variance in their adiponectin levels.

Body size and risk of prostate cancer in Jamaican men.

We investigated the associations between body size and risk of prostate cancer in a hospital-based case-control study in Jamaica. Height, weight, waist, and hip circumference were measured at enrollment, and data collected on medical and lifestyle factors for newly diagnosed cases (n = 243) and controls (n = 275). Compared with men in the normal range of waist-hip ratio (WHR), men with WHR > or =0.95 were at greater risk of total prostate cancer (OR,1.72; CI, 1.01-3.00) and high-grade cancer (OR, 2.02; CI, 1.03-3.96). With additional control for BMI, the association with WHR remained significant for total prostate cancer (OR, 1.90; CI, 1.01-3.53) and high-grade disease (OR, 2.94; CI, 1.34-6.38). There was no association between waist circumference and cancer without control for BMI but after controlling for BMI, waist circumference >90 cm (OR, 2.45; CI, 1.01-5.94) and >102 cm (OR, 5.57; CI, 1.43-18.63) showed a dose-response relationship with high-grade disease. Height and BMI were not associated with risk of prostate cancer. Abdominal obesity may be associated with risk of high-grade prostate cancer. Risk may be greater in those with higher abdominal obesity relative to overall size. The results further highlight the importance of investigating relationships by characteristics of the tumor.

The association of hypothalamic-pituitary-adrenal axis activity and blood pressure in an Afro-Caribbean population.

Hyperactivity of the hypothalamic-pituitary-adrenal axis (HPAA) resulting from fetal programming may play a role in the development of high blood pressure (BP) in black people. We assessed the diurnal salivary cortisol profile in children with and without increased BP and evaluated their mother's HPAA. In a cross-sectional study, 20 Afro-Caribbean children (mean age 9.6 years) with higher blood pressures and 20 children with lower blood pressures were chosen from a prospective study of 569 mothers and children in Jamaica. Daytime salivary cortisol profiles were collected in the children and their mothers. The mothers were also assessed for features of the metabolic syndrome. Children with higher BP had higher mean morning salivary cortisol concentrations than those with lower BP (7.9 S.D. 1.9 vs. 4.5 S.D. 2.4nmol/l; p=0.03). Their mothers also had increased morning salivary cortisol concentrations (9.9 S.D. 1.8 vs. 5.5 S.D. 2.5nmol/l; p=0.02), but no changes in fasting glucose, insulin, lipids, BP or adiposity. Maternal and offspring cortisol concentrations correlated significantly (r=0.465, p=0.004). Maternal cortisol concentrations were significantly associated with the child's BP. We conclude that Afro-Caribbean children with higher BP have higher morning salivary cortisol concentrations. The children's cortisol concentrations correlate significantly with the mother's cortisol concentrations. These findings suggest that the HPAA may play a role in the development of raised BP in Afro-Caribbean people.

Impact of adiponectin and ghrelin on incident glucose intolerance and on weight change.

OBJECTIVES: Adiponectin and ghrelin are associated with adiposity and type 2 diabetes in several studies. We sought to prospectively determine the interaction of adiponectin and ghrelin in the development of adiposity and hyperglycaemia. DESIGN: Prospective observational study. PARTICIPANTS: 393 community-dwelling Afro-Jamaicans (mean age 47 +/- 13 years; BMI 27.3 +/- 6.3 kg/m(2); 63% women) without glucose intolerance at baseline. MEASUREMENTS: Anthropometry, fasting plasma glucose, 2-h plasma glucose, insulin resistance (HOMA-IR), adiponectin and ghrelin concentrations were measured at baseline and 4.1 +/- 0.9 years later. Multivariate analyses were used to explore the associations of HOMA-IR, adiponectin and ghrelin with weight change and glycaemia. Results The mean weight change was 2.6 +/- 5.5 kg. There were 114 incident cases of impaired glucose tolerance (IGT) and 35 cases of diabetes mellitus. Adiponectin was positively correlated with age and female sex (P-values < 0.01). After adjusting for age and sex, adiponectin and ghrelin were significantly correlated with weight at baseline and follow-up. However, they were not associated with weight change even after further adjustment for baseline weight. Adiponectin, but not ghrelin, was associated with 2-h glucose concentrations at follow-up even after adjusting for age, sex, HOMA-IR and BMI (P = 0.04). In the fully adjusted logistic regression model, adiponectin predicted incident IGT (OR 0.93; 95% CI: 0.87-0.99) and attenuated the effect of BMI on incident IGT. CONCLUSIONS: These longitudinal data show that adiponectin and ghrelin may not be causally involved in the development of obesity. However, adiponectin is independently associated with decreased risk of incident IGT.

Isoprostanes, a marker of lipid peroxidation, may not be involved in the development of glucose intolerance.

We investigated whether isoprostanes, as a marker of lipid peroxidation, may be involved in the development of impaired glucose tolerance (IGT) or diabetes. Using a nested case-control study, we tracked the changes in isoprostane levels, insulin sensitivity (IS) and beta-cell function (BCF) in Afro-Jamaicans who progressed to IGT and diabetes over 3.9 years. Anthropometry, glucose tolerance, insulin levels, blood pressure and urinary isoprostane concentration were measured at baseline and follow-up. IS and BCF were estimated by the method of homeostasis assessment. Fifty-two individuals who progressed to IGT or diabetes and 44 age, sex and body mass index (BMI) matched controls were studied. Progression to glucose intolerance was significantly related with baseline BCF (p< or =0.01), but not isoprostane levels or IS. Glucose concentrations (fasting and 2 h) on follow-up were significantly correlated to baseline IS, baseline BCF, follow-up IS and follow-up BCF (p-values<0.05). In multiple regression analysis, only follow-up IS and BCF (p-values< or =0.001) independently predicted fasting glucose and 2h glucose levels at follow-up. Isoprostanes were not significantly associated with IS or BCF (p-values>0.1). We concluded that isoprostanes may not be causally involved in the development of glucose intolerance, insulin resistance or deteriorating BCF.

Maternal body composition, offspring blood pressure and the hypothalamic-pituitary-adrenal axis.

We tested the hypothesis that women who are thin or have poor pregnancy weight gain have offspring with higher blood pressure and examined whether this link is mediated by increased secretion of cortisol. We studied a cohort of 388 children born in Kingston, Jamaica. From hospital records we obtained information about their mother's body mass index (BMI) and weight gain during pregnancy. At age 8.5 years we measured the children's fasting plasma cortisol concentrations and blood pressure and assessed their mother's anthropometry. There were no relationships between the mother's BMI or weight gain during pregnancy and offspring blood pressure. However, mothers with a greater subscapular to triceps skinfold thickness ratio (SSTR) had offspring with higher blood pressure (5.6 mmHg systolic and 3.7 mmHg diastolic increase per unit change in SSTR, P = 0.002 and P = 0.008 respectively). Fasting plasma cortisol concentrations correlated with the children's systolic (r = 0.33, P < 0.0001) and diastolic pressures (r = 0.12, P = 0.02) independently of age, gender, weight or socio-economic status and were also predicted by the mother's SSTR. These findings suggest that maternal truncal obesity rather than thinness is associated with raised blood pressure in the offspring, and that this link may be mediated by increased cortisol secretion.

Impaired glucose regulation in adults in Jamaica: who should have the oral glucose tolerance test?

OBJECTIVE: To compare the 1999 World Health Organization (WHO) fasting plasma glucose (FPG) criteria and the WHO 2-hour post-challenge glucose (2hPG) criteria during an oral glucose tolerance test (OGTT) in identifying adults in Jamaica with hyperglycemia. As the OGTT is not commonly used in clinical practice, factors associated with the failure of the FPG criteria to detect persons with impaired 2hPG were investigated. METHODS: A random sample of 2 096 adults, 25-74 years old, living in the town of Spanish Town, Jamaica, was evaluated for diabetes. After excluding 215 individuals for reasons such as missing data, the remaining 1 881 persons were composed of 187 who were previously known to have diabetes and 1 694 who were screened for diabetes with both FPG and 2hPG. RESULTS: The FPG criteria detected 83 cases of diabetes, compared to 72 by the 2hPG criteria. The kappa statistic comparing the two criteria was 0.31 (95% confidence interval: 0.28-0.34), indicating fair agreement. There were 261 cases of impaired glucose tolerance (IGT) and 92 cases of impaired fasting glucose (IFG). In those 92 with IFG, an OGTT would identify 34 cases of IGT and 14 cases of diabetes. Of those classified as normoglycemic by FPG criteria, 14% of them had IGT or diabetes by 2hPG criteria. The factors predicting the likelihood of non-detection of impaired glucose tolerance or diabetes by FPG were age, body mass index, central obesity, systolic blood pressure, and female sex. By receiver operating characteristic curve analysis, an FPG of 5.1 mmol/L would predict a 2hPG >/= 7.8 mmol/L. CONCLUSIONS: A few individuals classified as normal on FPG will have IGT or diabetes, and an OGTT will be needed to identify them. The yield of IGT detected by screening in Jamaica can be improved by lowering the threshold for IFG or by using clinical information to identify high-risk individuals.

Impaired glucose regulation in adults in Jamaica: who should have the oral glucose tolerance test?

OBJETIVO: Comparar los criterios publicados por la Organización Mundial de la Salud (OMS) en 1999 acerca del uso de la prueba de glucemia en ayunas (PGA) y de la prueba de tolerancia a una dosis oral de glucosa con valoración a las dos horas (PTG2h) para identificar a adultos hiperglucémicos en Jamaica. Como la PTG2h no se administra normalmente en un contexto clínico, se investigaron los factores asociados con la inutilidad de la PGA para detectar a personas con hiperglucemia según la PTG2h. MÉTODOS: Se examinó una muestra aleatoria de 2 096 adultos de 25 a 47 años de edad que vivían en la ciudad de Spanish Town, Jamaica, para determinar la presencia de diabetes. Una vez que se eliminó a 215 personas por diversos motivos, entre ellos la ausencia de datos, quedaron 1 881 personas entre las cuales se encontraban 187 que se sabía de antemano que tenían diabetes y otras 1 694 que fueron sometidas tanto a la PGA como a la PTG2h. RESULTADOS: La PGA permitió detectar 83 casos de diabetes, mientras que la PTG2h permitió detectar 72. El estadístico kappa de comparación entre los dos criterios de valoración fue de 0,31 (intervalo de confianza de 95%: 0,28û0,34), valor que revela una concordancia moderada. Se observaron 261 casos de intolerancia a la glucosa tras la PTG2h y 92 casos de hiperglucemia en ayunas. En estas últimas 92 personas, la PTG2h sirvió para identificar 34 casos de intolerancia a la glucosa y 14 casos de diabetes. De las personas que se mostraron normoglucémicas según la PGA, 14% tenían intolerancia a la glucosa o diabetes, según la PTG2h. Algunos factores tuvieron valor pronóstico en relación con la falta de detección de la intolerancia a la glucosa o la diabetes. Estos fueron la edad, el índice de masa corporal, la concentración de la obesidad en el tronco y el abdomen, la tensión sistólica y el sexo femenino. De acuerdo con la curva de eficacia diagnóstica, una glucemia en ayunas de 5,1 mmol/L tendría valor pronóstico con respecto a la presencia de una glucemia de 7,8 mmol/L según la PTG2h. CONCLUSIONES: Algunas personas cuya glucemia en ayunas está dentro de lo normal tienen intolerancia a la glucosa o diabetes; por lo tanto, para identificarlas es necesario hacer la PTG2h. Se puede mejorar la detección de casos de intolerancia a la glucosa en Jamaica si se reduce el umbral de normalidad para la PGA o si se toman en cuenta los datos clínicos para identificar a las personas en alto riesgo.

The relationship among circulating insulin-like growth factor (IGF)-I, IGF-binding proteins-1 and -2, and birth anthropometry: a prospective study.

Fetal IGF-I is a determinant of birth weight, but whether maternal IGF-I plays a significant role is controversial. We sought to examine the relationships among maternal IGF-I, IGF-binding protein (IGFBP)-1, and IGFBP-2, with maternal and newborn anthropometry, in a cohort of 325 nondiabetic pregnant women of African origin. Blood was collected for IGF-I, IGFBP-1, and IGFBP-2 at 9, 25, and 35 wk gestation and in cord blood at delivery. In the second and third trimesters, maternal IGF-I was significantly correlated (P < 0.005) with maternal body mass index and triceps skinfold thickness. Maternal IGFBP-1 and -2 had an inverse correlation (P < 0.0001), with maternal anthropometry. Maternal IGF-I at 35 wk, and fetal IGF-I by cord blood were significantly correlated with birth weight (P = 0.001 and 0.048, respectively). IGFBP-1 in the third trimester and cord blood were negatively correlated with birth weight (P = 0.012 and 0.002). In multiple regression analyses, maternal IGF-I at 35 wk, fetal IGF-I, maternal weight at the first antenatal visit, gender, and gestational age were significant independent factors in the determination of birth weight. In conclusion, maternal IGF-I levels, especially during late pregnancy, positively influence birth weight.

Predicting incident diabetes in Jamaica: the role of anthropometry.

OBJECTIVE: To evaluate the performance of the body mass index (BMI), waist circumference, waist-to-hip ratio (WHR), and waist-to-height ratio (WHTR) in predicting incident diabetes in Jamaica. RESEARCH METHODS AND PROCEDURES: A cohort of 728 nondiabetic adults (290 men and 438 women), ages 25 to 74 years and residents of Spanish Town, Jamaica, were followed for a mean of 4 years. Participants had fasting and 2-hour postchallenge glucose concentrations measured at baseline and follow-up. RESULTS: There were 51 cases of incident diabetes (17 men and 34 women). All indices were independent predictors of diabetes, and none was clearly superior. The area under the receiver operating characteristics curves (95% confidence interval) for BMI was 0.74 (0.59 to 0.88) for men and 0.62 (0.51 to 0.72) for women. For waist circumference, these values were 0.78 (0.65 to 0.91) in men and 0.61 (0.50 to 0.71) in women. Similar results were obtained for WHR and WHTR. "Optimal" cut-off points for BMI were 24.8 kg/m(2) (men) and 29.3 kg/m(2) (women). For waist circumference, these were 88 cm and 84.5 cm for men and women, respectively. Corresponding values for WHR were 0.87 and 0.80 and for WHTR were 0.51 and 0.54, respectively. DISCUSSION: Cut-off points for waist circumference and WHR were similar to those proposed in developed countries for women but lower in men. Waist circumference could be useful in health promotion as an alternative to BMI.