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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

The effects of birth weight and postnatal linear growth retardation on body mass index, fatness and fat distribution in mid and late childhood.

Objective: To determine the effects of birth weight and early childhood stunting on body mass index (BMI), body fat and fat distribution at ages 7 and 11 years, and the change from 7 to 11 years.

Design: Prospective cohort study

Setting: Kingston, Jamaica.

Subjects: One hundred and sixteen stunted children (height-for-age below two standard deviations (<-2SD) of the National Center for Health Statistics (NCHS) references) and 190 non-stunted children (height-for-age > -1SD), identified at age 9-24 months.