Inter-relationships between percentage body fat, relative subischial leg length and body mass index among adolescents and adults from the Limbu community of Darjeeling, West Bengal.

Leg length in humans is considered to be an indicator of the long-term impact of quality of childhood living conditions and nutritional status. The main objective of this study was to evaluate the magnitude of association of percentage body fat (PBF) with relative subischial leg length (RSLL), adjusting for age, sex and body mass index (BMI), among adolescents and adults in a population of poor socioeconomic background in India. Data were taken from a cross-sectional study conducted in 2010-2014 among the Limbu community of Darjeeling, West Bengal - an indigenous community with poor socioeconomic background, low literacy rate, low income and inadequate living conditions. The study villages were located in the Himalayan and sub-Himalayan regions of Darjeeling. The present study sample comprised 97 adolescents aged 16-19 years (47 boys, 50 girls) and 260 adults aged 20-39 years (135 men, 125 women). Anthropometric measurements of stature/height (cm), weight (kg), sitting height (cm) and skinfold thicknesses (biceps, triceps, subscapular, suprailiac) (mm) were recorded. Derived variables were BMI (kg/m2), subischial leg length (SLL) (cm), RSLL (%), sum of four skinfolds (mm) and PBF (%). Significant sex differences at p<0.05 were observed for all anthropometric characteristics, except for body weight among adolescents and RSLL, subscapular and sum of four skinfolds in adults. The linear regression models adjusting for age and sex showed that RSLL had a negative relationship with PBF (p<0.05) among adolescents and adults. Higher body fat, independent of BMI, was correlated with lower RSLL among both adolescents and adults from the Limbu community, indicating a possible association with poor quality living conditions in childhood. However, this may also have been due to the allometry of total body fat with body proportions - a relatively larger trunk results in more body fat.