Objective: To investigate the dietary fiber intake status and analyze the relationship between dietary fiber and glucose metabolic disorder of the elderly in China.
Methods: Data were collected from the participants of Chinese adult chronic diseases and nutrition surveillance in 2015. General information were collected by standardized questionnaires, anthropometric index and blood pressure of respondents were measured according to standard method. Food intake was collected by three consecutive day 24 h dietary recalls, dietary fiber was calculated through China food composition. Fasting venous blood were collected to measure glucose, HbA1C, and other related biochemical index. Subjects were divided into three groups: normal glucose(NG, normal glucose), pre-diabetes(Pre-DM, pre-diabetes mellitus) and diabetes(T2DM, type 2 diabetes mellitus). Multiple logistic regression model was used to analyze the relationship between dietary fiber intake and Pre-DM as well as T2DM.
Results: A total of 20 996 elderly people aged 60 years and above were included. There 10 773 cases were males(51.3%) and 10 223 cases were females(48.7%), the age of both gender were(68.21±6.26) years and(67.67±6.26) years. A total of 6526 cases of pre-diabetes were detected in 20 996 elderly participants with detection rate of 31.1%. There 3274 cases were male and 3252 cases were female, the detection rates of both genders were 30.4% and 31.8%, respectively. While 1572 participants were detected as T2DM(784 of males and 788 of females), the detection rate of T2DM was 7.5%, 7.3% for males and 7.7% for females. There were significant differences in mean age, BMI, waist circumference, systolic blood pressure, diastolic blood pressure, TC, TG, HDL-C, LDL-C, HbA1c level among different dietary intake groups(P<0.005). With the increase of dietary fiber intake, the proportion of overweight and obesity, central obesity and dyslipidemia showed an increasing trend(P<0.05), and the proportion of hypertension showed a decreasing trend(P<0.000 1). After adjusting for potential confounding factors, compared to participants with lowest fiber intake, participants in subgroups of lower, minor lower, and higher fiber intake were associated with decreased risk of pre-diabetes, the OR and 95%CI were(OR=0.911, 95%CI 0.835-0.993), (OR= 0.861, 95%CI 0.790-0.938) and(OR= 0.913, 95%CI 0.838-0.994), respectively. However, there was only a statistically significant negative association between the higher intake of dietary fiber and T2DM(OR = 0.848, 95%CI 0.726-0.991).
Conclusion: Dietary fiber intake was negatively related with diabetes and pre-diabetes mellitus. The risk of glucose metabolic disorder was decreased with the increase of dietary fiber intake.
Keywords: cross-sectional study; dietary fiber; elderly; type 2 diabetes.