Certain risk factors have been shown to cluster with clinical conditions like obesity, type 2 diabetes and cardiovascular problems. Such clustering of risk factors have led investigators to propose a new condition called cardiometabolic risk syndrome. Cardiometabolic risk has gained much attention recently and has been linked directly with visceral adiposity. Few investigations have implicated a direct link between centrally obese men and low levels of testosterone. Association of Testosterone with insulin resistance, obesity, diabetes and atheroschlerosis has been presented earlier but has not received much attention. Higher incidence of metabolic syndrome has also been hypothesized to be associated with decline in testosterone levels. There is evidence that testosterone replacement therapy results in reduced insulin resistance and central obesity in type 2 diabetic men. In this study, we have investigated relationship between testosterone and markers of cardiometabolic risk.
A cohort of male patient samples from ZRT database was selected for the study and categorized in tertiles based on testosterone levels with low (<300),>800). The relationship between testosterone levels and cardiometabolic risk was evaluated using bloodspot testing of insulin, hemoglobin A1c, triglycerides and high sensitivity c-reactive protein. All bloodspot assays were developed in house and showed good correlations with serum/plasma levels of risk markers tested.
A total of 124 male patient samples (41 with testosterone levels <>800 ng/dL) were tested for cardiometabolic risk markers. Mean age (+/- SD) was 50.8 (+/- 12.8). Insulin (4.7 µIU/mL) and high sensitivity c-reactive protein (1.83 mg/L) were found to be significantly lower in the highest tertile with testosterone levels greater than 800 ng/dL when compared with insulin (6.3 µIU/mL) and hs-CRP (3.46 mg/L) concentrations in the lowest tertile with testosterone levels less than 300 ng/dL. There was no significant difference observed in HbA1c and triglyceride levels in different groups.
Our data suggest that a higher testosterone level in men is associated with lower CRP and insulin concentrations. These patients may have a lower risk of developing metabolic syndrome and/or atheroschlerotic cardiovascular events.