Osteoprotegerin is not a determinant of metabolic syndrome in sub-Saharan Africans after age adjustment.

OBJECTIVES: Osteoprotegerin (OPG), a soluble member of tumor necrosis factor receptor superfamily that inhibits bone resorption, has been suggested as a cardiovascular risk factor in humans. In this study, we aim to investigate the potential relationship between OPG and MetS (MetS) in a sub-Saharan African population. METHODS: Four hundred and eleven volunteers (152 men, 259 women) aged ≥18 years recruited from the general population in Douala and Edea, Cameroon participated in this study. Anthropometric parameters measured and blood samples were collected for glucose, serum lipids and OPG concentrations measurements. Mean differences of the variables in different groups were compared using Students' t test. We performed logistic regressions to analyze the impact of independent factors on the relation between OPG and MetS outcome. MetS was defined using the Joint Interim Statement 2009. RESULTS: OPG levels did not vary significantly between both men and women with and without MetS (both P>0.05). However, with high fasting blood glucose (≥5.6 mmol/L) had a significantly higher OPG level than those with lower glucose level (P=0.014). In multiple logistic regression analysis, MetS did not show any significant association with serum OPG levels in men and women after adjusting for age, physical activity, alcohol consumption and menopausal status in women (P=0.720 and P=0.930 respectively). CONCLUSION: This study failed to demonstrate any relationship between OPG and MetS. Nevertheless, the positive association between blood glucose and OPG levels reveals that OPG might be involved in cardiovascular risk development in this sub-Saharan African population.

Development of a highly sensitive and specific new testosterone time-resolved fluoroimmunoassay in human serum.

A new time-resolved fluoroimmunoassay (TR-FIA) of testosterone in serum is described, using a biotinylated testosterone tracer, with a long spacer arm between biotin and testosterone, coupled to the C3 of the testosterone: a biotinylaminodecane carboxymethyloxime testosterone. This tracer affords a great sensitivity of the standard curve, because a amount of 0.3 pg of testosterone can be significantly measured on the testosterone standard curve. The "functional" sensitivity is at least equal to 21 pg/ml of serum. The specificity of the assay is insured by a celite chromatographic step on new minicolumns before immunoassay. The variation coefficient of inter-series reproducibility measured on low and normal testosterone levels in untreated and testosterone treated hypogonadal men were between 2.17 and 5.07%. The accuracy test, (overload and dilution tests) gave satisfying results. Moreover, in a comparison with GCMS, it appeared that the correlation coefficient was 0.992 and no significant difference could be exhibited between the two methods. Consequently, this specific, sensitive reproducible and easy to use method is well suited to the measurement of testosterone in clinical and pharmacological conditions.