ISSN No. 1606-7754                   Vol.14 No.1  April 2006

High levels of F2-Isoprostanes in Jamaican adults with diabetes mellitus
A O’Connor,1 N McFarlane-Anderson,¹ EM Duff,² R Wright-Pascoe,³ YB Wint2
Department of Basic Medical Sciences,¹ The University of the West Indies School of Nursing,²Department of Medicine,³ Faculty of Medical Sciences, The University of the West Indies, Kingston, Jamaica

Abstract

Inadequate glycaemic control in Jamaican adults with type 2 diabetes mellitus (DM) prompted assessment of glycaemic control, oxidative stress, cardiovascular (CV) and renal risk in adults attending a hospital clinic. A random sample of 133 patients men (n=35) and women (n=98), with diabetes mellitus was selected from a population of 510 patients. Fasting blood samples (n=122) were evaluated for metabolic control and dyslipidaemia. Oxidative stress was evaluated by measurement of urinary F2 isoprostane (n=124). The data were analysed using SPSS. The mean age of the participants was 56.7 ± 14.3 years, with mean duration of diabetes of 12.2 years. Mean fasting blood sugar was 8.6 ± 4.3 mmol/L. 77% of patients had HbA1c > 6.5%. 69% of patients were being treated with insulin with no difference in HbA1c levels in these patients compared to those receiving other hypoglycaemic agents. 90% of men (median 1004pg/mg creatinine) and 99% of women (median 1501.3pg/mg) had isoprostane levels above the median for subjects with CV risk. 54% of patients had total cholesterol levels ≥ 5.2 mmol/L, 16% triglyceride levels ≥ 1.5 mmol/L, 25% HDL levels ≤ 1.0mmol/L and 86% LDL ≥ 2.5mmol/L. 63 % of patients had BP >130/85 mmHg. 81% were overweight or obese, with 80% of the men having waist circumferences >88 cm, whereas 87% of the women had waist circumferences of 84.5cm. Microalbuminuria was increased in 37% of the subjects. The high prevalence of overweight, central obesity, elevated LDL and hypertension in these patients indicated high CV and renal risk. The risk was significantly higher in persons with inadequate glycaemic control. Isoprostane levels were high in the majority of subjects but did not correlate with HbA1c or any other variable. (Int J Diabetes 14: 51-54, 2006 )

Key words: Isoprostanes, cardiovascular risk, renal risk, BMI

Introduction

Hyperglycaemia increases the risks for the chronic complications of diabetes and thus increases morbidity and mortality. Improved glycaemic control may prevent the appearance and enhance the regression of macrovascular and microvascular complications. Macrovascular complications make the greatest contribution to the burden of diabetes1 and are decreased with glycaemic control.2 The prevalence of DM is high in Jamaica and the Caribbean and many patients have poor metabolic control.3,4

Heart disease is the leading cause of death in persons with DM.5 Cardiovascular (CV) disease in diabetes is multifactorial and risk factors include hypertension, dyslipidemia, insulin resistance and central obesity.6 Recently, oxidative stress has been suggested as another potential mechanism. Possible sources of oxidative stress in DM include altered carbohydrate and lipid metabolism and decreased levels of antioxidant defenses. Investigation of oxidative stress may therefore be useful in understanding DM and CV disease. Growing evidence suggests that isoprostanes are reliable and sensitive markers of in vivo lipid peroxidation. Studies have shown an effect of glucose on oxidative stress, and positive associations between indices of obesity such as BMI and waist/hip ratio and urinary levels of 8-epi-PGF2a. Insulin itself promotes hydrogen peroxide generation in fat cells, prompting speculation that oxidative stress is a mechanism of insulin resistance in chronic hyperinsulinaemia.7 A previous study on subjects with at least one CV risk factor but no history of CV disease, reported a median (range) of 141 (67-498) pg/mg creatinine in subjects treated with vitamin E supplementation and 148 (76-561) pg/mg creatinine in untreated subjects.8 Another study reported high values in subjects with android obesity.9

Hypertension is known to be a major risk factor for the development of diabetic renal disease and hyperglycaemia also has a role in the development of diabetic nephropathy.10 Microalbuminuria is a predictor of CD disease and renal failure in populations of European origin and in other races such as Australian Aborigines.11 This study therefore sought to assess the level of glycaemic control and indicators for CV and renal risk, including oxidative stress, in adults attending a hospital clinic in Jamaica.

hndarrw01d.gif (182 bytes)

Table of Contents

Back to
Contents