A Study on the Association of Diet Quality and Risk of Mortality and Major Chronic Diseases from Nationally Representative Longitudinal Data

Abstract

The objectives of this study investigated association between the risk of mortality and morbidity of major chronic diseases and the nutritional intake status/diet quality using a national longitudinal data from Korean population. Data of 8,941 men and women aged 30+ from 1998 and 2001 Korea National Helath and Nutrition Examination Surveys (K-NHANES), collected from a stratified multistage probability sample of South Korean households, were individually linked to national death certificate data and national insurance hospitalization data during 4~7 year follow up through 2005. K-NHANES linked data have strong advantage of including a variety of variables such as socioeconomic status, nutritional risk factors and baseline health status as well as health behaviors, biological risk factors. Cox’s proportional hazard models were used in this study to estimate relative risks and their 95% confidence intervals of mortality (all-cause and cause-specific), morbidity (selected diseases) according to status of nutrional intake and diet quality indexes. Since studies of the association between diet quality and death and diseases in Western counties, until now, a few studies have used longitudinal data with representativeness for Korean population. The analysis for relationship between diet quality and mortality and morbidity of major chronic diseases showed that nutritional factor and diet quality could contribute to the lower risk mortality and major chronic diseases in Korean population. The low-quality diet group showed a significantly higher risk of mortality compared with high-quality diet group. The risks of incidence of cardiovascular disease, cerebrovascular disease, cancer were also significantly higher among the low-energy intake group. Also, the low-quality diet group had more episodes of hospitalization of selected diseases.