Objectives: An increasing number of lifestyle disorders have emerged in response to the rapid urbanization that has occurred in Thailand. Recently, leptin resistance has been nominated as a possible marker for the onset of metabolic disorders in Asian countries. The research aimed to assess the relationship between leptin-resistance and environmental and/or genetic factors by comparing urban and rural inhabitants in Thailand.
Methods: A total of 212 age- and sex-matched subjects from an urban area (Bangkok) and from rural areas (Sai Noi) participated in the study. Anthropometric measurements, blood biochemistry, single nucleotide polymorphism analyses, and interviews concerning lifestyles and dietary habits were conducted individually. Backward elimination multiple regression analyses and least trimmed sum of square methods were used to estimate the effects of possible factors.
Results: A transition of staple food from rice to bread (decreased rice intake; p < 0.01 and increased bread intake; p < 0.05) was significant in urban areas. Leptin levels were higher in urban groups, with a significant difference in women (p < 0.001 in women and p = 0.06 in men), but not in men. Predictors selected for leptin-resistance in women were genotypes of UCP2, PPARg2, bread intake, living area, and smoking habit (r = 0.510); in men, genotypes of UCP2 and UCP3p, smoking habit, and rice intake (r = 0.315).
Conclusions: Urban women with del/del type of UCP2 exhibited significant leptin resistance. A combination of urbanization and UCP2 genotype were considered to be responsible.