Relationship of second-to-fourth digit ratio with metabolic syndrome indices and serum biomarkers in Hausa ethnic group of Kano, Nigeria

BACKGROUND: High prevalence levels of the metabolic syndrome (MetS) in developed and developing countries and the associated high mortality and morbidity are forcing scientists to explore promising therapeutic agents and population-specific anthropometric criteria for defining its phenotype. OBJECTIVES: The aim of this study is to investigate the relationship between digit length and second-to-fourth digit ratio (2D:4D) with the indices of MetS and its serum biomarkers. MATERIAL AND METHODS: The study was a cross-sectional study which included 465 (266 males and 199 females) Hausas of Kano, with a mean age of 34.4 years and 32.0 years for males and females, respectively. Systematic random sampling technique was employed for subject recruitment. Height, weight, waist circumference, body mass index, and digit lengths were obtained using standard protocol. Overnight fasting blood sample was obtained for fasting blood glucose, high density lipoprotein cholesterol (HDL-c), total cholesterol, triglycerides, low-density lipoprotein, uric acid, and adiponectin estimation using standard laboratory protocols. Blood pressure was measured following standard clinical procedure. Pearson's correlation was used to test the association between the digit lengths, 2D:4D with MetS indices, uric acid, and adiponectin. To compare between-group parameters of males and females, left and right hand, Student's t-test and one-way ANOVA were used. SPSS version 20 software was used for statistical analyses and P < 0.05 was set as level of significance. RESULTS: 2D:4D showed significant positive correlation with uric acid, blood pressure, and serum parameters of MetS. A negative correlation was observed between 2D:4D, adiponectin, and HDL. In both sexes, the R2D:4D had stronger correlation with MetS indicators when compared with the L2D:4D. CONCLUSION: 2D:4D is good correlate of metabolic risk parameters and R2D:4D correlates better than L2D:4D.