C. E. Ezenwaka

Aim: To determine how the levels of leptin and monocyte chemotactic protein-1 (MCP-1) are associated with insulin resistance (IR) in obese, non-obese, diabetic and non-diabetic subjects. Methods: 112 type 2 diabetics and 43 non-diabetics were studied fasting. Anthropometric indices were measured and glucose, insulin, leptin and MCP-1 were measured in blood. IR was calculated. Results: MCP-1 level was significantly higher in diabetics than non-diabetics irrespective of gender (p < 0.05). Irrespective of diabetes status, the serum leptin concentration was significantly higher (p < 0.05) in obese and females subjects than in non-obese and male subjects respectively. There were no significant correlations between IR and MCP-1 or leptin in all subgroups of subjects studied. General linear modelling analysis showed that only diabetes state significantly predicted MCP-1 levels (p < 0.05) whereas non of the factors predicted leptin levels (p > 0.05). Conclusion: Routine measurement of leptin and MCP-1 would be potentially useful in assessment of patients for the metabolic syndrome or coronary heart disease especially in black population.

Background and aim: Tobago and Trinidad are two Caribbean islands with distinct genetic background and lifestyles; while Tobago is serene and a tourist centre, Trinidad is characterized by a hustling and bustling lifestyle. The study was aimed at determining and comparing the prevalence of the metabolic syndrome (MetS) and its critical components in type 2 diabetic patients using the new International Diabetes Federation (IDF) definition. Methods: Four hundred and thirteen (166 Tobago, 247 Trinidad) type 2 diabetic patients visiting 10 lifestyle disease clinics were studied. Blood pressure, anthropometric parameters (height, weight, body mass index and waist circumference) and overnight fasting blood samples were taken. Plasma glucose and serum triglycerides, total cholesterol, LDL- and HDL-cholesterol, insulin, and adiponectin were determined. Insulin resistance (IR) was determined using the HOMA method. Results: The patients in Tobago were significantly older than patients in Trinidad (p < 0.001) but the duration of diabetes (9.4 ± 0.5 vs. 11.1 ± 0.7 yr), medications, generalized (31.7 vs. 38.8%) and central (78.5 vs. 83.7%) obesity were similar (p > 0.05). In comparison with patients in Tobago, diabetic patients in Trinidad, irrespective of gender, had significantly higher prevalence of IDF critical components such as raised BP, raised triglycerides and reduced HDL-cholesterol (all, p < 0.001). Thus, while more patients in Trinidad were diagnosed with MetS based on three or four components, more patients in Tobago were diagnosed based on two components (p < 0.001). Conclusions: There were high prevalence rates of the components of the MetS in both the islands of Tobago and Trinidad. Quantitatively, the aggregation of the components is higher in patients in Trinidad, which constitute greater risk for adverse cardiovascular outcome. Controlling central obesity should be the target in preventing MetS in the two islands.

Low adiponectin levels are associated with elevated plasma alanine aminotransferase, a marker of reduced hepatic insulin sensitivity and a risk factor for type 2 diabetes. This study aims to determine the relationship between serum adiponectin level and alanine aminotransferase in diabetic and non-diabetic subjects. Fifty-six type 2 diabetic patients and 33 non-diabetic subjects participate in the study. Baseline plasma concentrations of alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase and glucose are measured on a chemistry analyser. Insulin and adiponectin are measured using enzyme-linked immunoassay techniques and insulin resistance is determined using the homeostatic model assessment method. Diabetic patients showed significantly lower levels of serum adiponectin than did the non-diabetic subjects, whereas levels of alanine aminotransferase and alkaline phosphatase were similar in both groups. While female non-diabetic subjects showed higher serum adiponectin levels than did female diabetic patients, alanine aminotransferase level did not differ (P>0.05). No significant relationship was seen between adiponectin and alanine aminotransferase in diabetic and non-diabetic subjects (P>0.05). Serum adiponectin levels were higher in non-diabetic subjects but there was no significant correlation between adiponectin and alanine aminotransferase in both groups of subjects. The data suggest that low serum adiponectin level may not be a suitable marker for impaired liver function in diabetic patients.