Impact of lifestyle changes on stress in a modernizing rural population in Hainan Island, China

Abstract

Little is known about inter-individual variation in psychological stress in modernizing rural populations in developing countries. The objective of this study was to investigate the association between Epstein-Barr virus (EBV) antibody titer, a biomarker of psychological stress, and lifestyle parameters in rural communities in Hainan Island, China. EBV antibody titer was measured in dried blood spot (DBS) samples collected from 240 adults living in rural communities in Hainan Island. Measures of two major lifestyle changes in rural areas of Hainan Island, i.e., diet and commercial goods possession, were examined by using information on the weekly frequency of pork consumption and monthly mobile phone fees. Both parameters were standardized to create two composite scores: a total affluence index (TAI--the sum of these scores), and an investment tendency index (ITI--the difference between them). Least-squares regression analysis was used to investigate the association between EBV antibody titer and these lifestyle parameters. A positive association was found between the frequency f pork consumption and EBV antibody titer (P = 0.040), whereas a negative association was found between mobile phone fees and EBV antibody titer (P = 0.028). A negative association was also observed between ITI and EBV antibody titer (P = 0.002) after adjusting for the effect of TAI. Psychological stress among local residents was linked to the type of lifestyle changes they had experienced, where the adoption of a more market-oriented lifestyle, irrespective of current affluence, was associated with less psychological stress.