Impact of Early Life or Intrauterine Factors and Socio-Economic Interaction on Diabetes - An Evidence on Thrifty Hypothesis

Abstract

Diabetes mellitus is one of the most concerning non-communicable diseases worldwide. The prevalence of diabetes increased rapidly by the influence of socioeconomic interactions. The thrifty hypothesis postulates that certain genes that are involved in positive selection promote efficient fat deposition and storage. This is beneficial for the survival of mankind in adverse conditions. However, in this modern society, these genes have become disadvantageous as people are significantly less likely to experience famines and nutrition shortages. The socioeconomic development that has occurred during the 20th century induced abundance of food supplies in almost all regions of the world. This has led to a rapid rise in the prevalence of obesity, and type 2 diabetes as a consequence. Boom of diabetic pandemic in newly developed countries compare with others those who developed gradually can be explain by thrifty hypothesis, as a result of the difference in the exposure to environmental factors and famine by the ancestors leads. The globalization, urbanization, lack of physical activity, intake of high calorie food and migration is major cause of pandemic emergence of diabetes in high as well as middle and low-income countries.

Genetic and Environmental Factors Contributing to Visceral Adiposity in Asian Populations

“…This, however, becomes counterproductive and metabolically disadvantageous in times of overabundance, such as when transitioning from poverty to affluence, from labor-intensive work to sedentary lifestyles, or from traditional diets to westernized, processed meals [62]. More recent reevaluations of the hypothesis have led to modified versions such as the thrifty phenotype hypothe-sis (fetal and infant metabolic adjustments considered "nutritionally thrifty" are made in response to adverse early environments, such as famine and nutritional shortage), the thrifty genotype hypothesis (genes such as those that increase fat storage are not, in fact, selected for, but persist in the population due to genetic drift), and the thrifty epigenetic hypothesis (the acquisition of metabolic thrift occurs in the early developmental period when exposed to nutritionally disadvantageous environments; exposure alters expression of genetic factors and can be passed down and subsequently altered according to environmental conditions) [34,[63][64][65].…”

“…This is especially apparent in the diets of developing Asian countries, where globalization trends, internal modernization, and the growing appeal of Western-style fast food have led to increasingly westernized diets [ 32 , 33 ]. Dietary shifts from coarse grains to refined rice and wheat often accompany rapid economic development [ 34 ]. Moreover, second-generation Asian immigrants are more likely to diverge from their native country’s diet.…”

“…The direct transcription and translation of DNA and subsequent expression of the gene product has been well established as a non-linear process; post-translational modifications such as DNA methylation, histone modification, and phosphorylation provide additional avenues for regulation of gene expression [ 66 ]. Notable environmental features supporting epigenetic changes in fat distribution include early developmental exposure to adverse environments (poor nutritional intrauterine environment, famine exposure in early-life, poor childhood nutrition) which later present detrimental effects when exposed to nutrient-rich, sedentary environments, rapid modernization and economic development, significant lifestyle changes due to urbanization, and migration from underdeveloped to developed countries [ 34 ].…”

“…Historically, the European region appears to undergo fewer famine cycles than Asian regions of the world. This can be attributed to historical patterns of development: efficient trading and distribution systems, centrality in both land and sea commerce, and agricultural diversification through importation of New World crops via the Columbian Exchange [ 34 ]. Conversely, the Indian subcontinent endures frequent monsoon seasons where agricultural yield and food availability depend on seasonal fluctuations.…”

“…Repeating seasonal changes and resultant periods of starvation may be accompanied by metabolic alterations in which the body attempts to compensate by altering its metabolic functioning—and possibly anthropomorphic fat distribution—in order to maximize scarce resources and promote survival [ 71 ]. The feast-and-famine phenomenon may explain why the increase in diabetes within the population in the past decades has been lower for Europeans and higher for regions undergoing rapid economic change and modernization [ 34 ]. Though the initial proposition analyzed an increased incidence of diabetes within the population, we include it in light of the common relationship between increased incidence of diabetes and visceral fat deposition within the Asian population.…”