Introduction

The health effects of the alteration of traditional occupations, physical activity, and diets by exposure to modern ways of life have been described in many cross-national, cross-sectional, and longitudinal studies. The energetic and metabolic consequences of modernization, such as adiposity in adults and its role in cardiovascular disease (CVD) risk factors, have been the focus of most modernization studies. Fewer studies have been able to measure behavioral, attitudinal, and emotional factors, their physiological concomitants, and their associations with health and disease.

The purpose of this chapter is to describe the role of hormones associated with energy metabolism and the sympathetic nervous system (SNS) as they relate to changes in cardiovascular health and disease with modernization. The emphasis is on insulin, and its role in adiposity and psychophysiological stress in modernizing groups. CVD-related outcomes discussed here will largely be risk factors such as blood pressure and hypertension, lipid and lipoprotein levels, adiposity and catecholamine levels. Potential interactions between positive energy balance and psychophysiological arousal will be discussed because such interrelationships may elevate CVD risk in groups experiencing social and economic change. This unitary model of insulin's several effects on the two physiological and psychological systems will be exemplified by describing work among modernizing Samoans and how future studies could benefit from this integrative focus on hormones and lifestyle changes.