Reproductive ecology and life history of human males : a migrant study of Bangladeshi men

• Main Author: Magid, K. S.
• Published: University College London (University of London) 2011
• Subjects: 301
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.625689

Developmental constraints influence individual energetic apportionment between growth, maintenance and reproduction with long-term implications for health and longevity. Such life-history trade-offs are hypothesised to explain the observed variability of human male and female reproductive steroid levels. Salivary testosterone (salT), anthropometric, and demographic data were collected from: 1) sedentees in Sylhet, Bangladesh (n=107; aged 20-78 years, mean 39); 2) Bangladeshi born men who migrated to London as adults aged ≥18 (n=61; aged 23-76, mean 49); 3) Bangladeshi born men who migrated to London as youths <18 (n=50; aged 18-69, mean 32); 4) British born Bengalis (n=48; aged 18-42, mean 25); and Londoners of white British or other white European parentage from 5) similar socioeconomic background compared to migrant groups (n=58; aged 18-75, mean 41); and 6) higher status socioeconomic background compared to migrant groups (n=30; aged 22-54, mean 37). SalT and somatic markers of adult Bengalis is dependent upon the age at which they migrated from Bangladesh to the UK and suggests differences in male reproductive phenotype, health behaviours and diet due to changes in ecological conditions during development. These findings contribute to the growing body of evidence that salT, stature and apportionment of skeletal muscle vary in accordance with early life conditions and the strategic allocation of reproductive effort in the human male, with a corresponding increase in early symptoms of adult onset disease of the prostate and glucose metabolism, and low socioeconomic status (SES). Predicted blunting of diurnal salT profile in adult migrants was inconclusive. Contrary to the predictions of this study, Bengali men do not have lower salT in relation to reproductive status of paternity or marriage, while older British-born European men of low SES have higher salT in relation to number of offspring and marital status. British-born Bengalis and migrants who arrived as children under the age 12 years were revealed to be of significantly higher SES than migrants who arrived in London after the age 18, possibly reflecting a generational shift away from historical conditions of poverty within the London Bengali community.