Diet, alcohol consumption, and serum lipid levels of the middle-aged and elderly in the Guangxi Bai Ku Yao and Han populations

Abstract

Bai Ku Yao is an isolated subgroup of the Yao minority in China. The special customs and cultures including their clothings, intraethnic marriages, corn wine and rum intakes are still completely conserved to the present day. Little is known about the association of diet and alcohol consumption with serum lipid levels in this population. The aim of this study was to compare the differences in diet, alcohol consumption, and serum lipid levels of the middle-aged and elderly between the Guangxi Bai Ku Yao and Han populations. A total of 485 subjects of Bai Ku Yao and 501 participants of Han Chinese aged 40 and over were surveyed by a stratified randomized cluster sampling. Information on dietary intake and alcohol consumption was collected by standard questionnaires. Serum lipid levels were measured. Education level, height, weight, body mass index, waist circumference, blood pressure, hypertension, and total energy, fat, protein, dietary cholesterol, and salt intakes were lower in Bai Ku Yao than in Han (P < .05–.001), whereas physical activity level, carbohydrate, vegetal protein, and total dietary fiber intakes were higher in Bai Ku Yao than in Han (P < .001 for all). Serum total cholesterol, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), apolipoprotein (Apo) A1, and Apo B levels were lower in Bai Ku Yao than in Han (P < .001 for all). The levels of triglyceride, HDL-C, Apo A1, and the ratio of Apo A1 to Apo B in Bai Ku Yao were higher, but the levels of LDL-C and Apo B were lower in drinkers than in nondrinkers. The levels of triglyceride, HDL-C, LDL-C, Apo A1, Apo B, and the ratio of Apo A1 to Apo B in Bai Ku Yao were also influenced by the amount of alcohol consumed (P < .05–.001). High-density lipoprotein cholesterol levels in Han were higher and LDL-C levels were lower in drinkers than in nondrinkers (P < .01 for each). Serum total cholesterol, HDL-C, and LDL-C levels in Han were also associated with the amount of alcohol consumed (P < .05–.001). The differences in the lipid levels between the two ethnic groups may partially attribute to the differences in dietary habits and alcohol consumption.

Introduction

Epidemiologic studies have shown that dyslipidemia, especially high concentrations of serum total cholesterol (TC) (National Cholesterol Education Program, 1994), triglycerides (TGs) (Arai et al., 2005), low-density lipoprotein cholesterol (LDL-C) (Achari & Thakur, 2004), apolipoprotein (Apo) B (Kwiterovich et al., 1992), and low levels of high-density lipoprotein cholesterol (HDL-C) (Gordon et al., 1989), is a major risk factor for the development and progression of atherosclerosis and coronary artery disease (CAD). Serum lipid levels are associated with genetic factors (Austin et al., 1987) and environmental factors, such as diet (Bermudez et al., 2002), drinking (Savolainen & Kesaniemi, 1995), smoking (Craig et al., 1989), and exercise (Panagiotakos et al., 2003). Numerous studies have evaluated the influence of alcohol intake, an index of lifestyle, on plasma lipid and lipoprotein concentrations (Savolainen & Kesaniemi, 1995). A moderate intake of alcohol is associated with protection against CAD, probably due in part to a dose-dependent increase in HDL-C (Agarwal, 2002, Choudhury et al., 1994, De Oliveira E Silva et al., 2000). A decrease in LDL-C with increased alcohol intake has also been reported in some studies, but this effect is less consistent and probably depends on the combination of one or more unmeasured factors (Savolainen & Kesaniemi, 1995). However, alcohol consumption also promotes lipogenesis (You & Crabb, 2004) and accordingly increases serum TGs (Castelli et al., 1977).

There are 56 ethnic groups in China. Han is the largest ethnic group. During the past 20 years, China has experienced remarkable socioeconomic development, with the mean income increasing by severalfold. Consequently, the lifestyles of people in the developed areas have changed dramatically. The nutritional lifestyles have led to increased intakes of fat and cholesterol, which has gradually increased serum TC levels. Although several regional or national studies have shown that serum lipid concentrations were higher in a significant part of the population and that an increasing proportion of the population had dyslipidemia (He et al., 2004, Li et al., 2005, Zhao et al., 2007), little is known about the difference in the lipid levels between Han Chinese and other minority group in rural areas.

Bai Ku Yao (White-trouser Yao), a special branch of the Yao minority in China, is named for the men wearing white knee-length knickerbockers. The population size is about 30,000. Because of isolation from the other ethnic group, the special customs and cultures including their clothing, intraethnic marriage, corn wine and rum intakes are still completely conserved to the present day. We hypothesize that there may be significant differences in demographic characteristics, dietary patterns, lifestyle factors, and serum lipid levels between the two ethnic groups. Therefore, the present study was undertaken to compare the differences in diet, alcohol consumption, and serum lipid levels of the middle-aged and elderly between the Bai Ku Yao and Han populations from the same area.