Association of Serum Magnesium with Insulin Resistance and Type 2 Diabetes among Adults in China.

Magnesium is an essential mineral for the human body and a cofactor or activator for more than 300 enzymatic reactions, including blood glucose control and insulin release. Diabetes is a well-known global burden of disease with increasing global prevalence. In China, the prevalence of diabetes in adults is higher than the global average. Evidence shows that magnesium is a predictor of insulin resistance and diabetes. However, the majority of studies focus on dietary magnesium instead of serum magnesium concentration. We study the correlation of serum magnesium levels with insulin resistance and Type 2 diabetes. In this prospective cohort study, we included 5044 participants aged 18 years and older without insulin resistance (IR) and diabetes at the baseline from China Health and Nutrition Survey (CHNS). A fasting blood sample was taken for the measurement of both types of magnesium, fasting blood glucose, hemoglobin A1c (HbA1c), and fasting insulin. The homeostatic model (HOMA-IR) was calculated. Demographic characteristics of participants, and risk factors such as intensity of physical activities, smoking status, drinking habit, and anthropometric information were recorded. IR was defined as HOMA-IR ≥ 2.5, and Type 2 diabetes mellitus was defined as fasting plasma glucose ≥ 7.0 mmol/L or HbA1c ≥ 6.5%, or a self-reported diagnosis or treatment of diabetes. A total of 1331 incident insulin resistance events and 429 incident diabetic events were recorded during an average follow-up of 5.8 years. The serum magnesium concentration was categorized into quintiles. After adjusting for relevant covariates, the third quintile of serum magnesium (0.89−0.93 mmol/L) was correlated with 29% lower risk of incident insulin resistance (hazard ratio = 0.71, 95% CI 0.58, 0.86) and with a lower risk of Type 2 diabetes. Multivariable-adjusted hazard ratios (95% confidence intervals) for insulin resistance were compared with the lowest quintile of serum magnesium (<0.85). We found similar results when evaluating serum magnesium as a continuous measure. Restricted cubic spline (RCS) curves showed a nonlinear dose−response correlation in both serum magnesium levels and insulin resistance, and in serum magnesium levels and Type 2 diabetes. Lower serum magnesium concentration was associated with a higher risk of insulin resistance and diabetes.

[Snacking behaviors of Chinese female adults aged 18 to 49 years old in 2004-2015].

OBJECTIVE: To describe shift in snacking behavior among Chinese female adults aged 18 to 49 years old in 2004-2015, and to analyze the contribution of snacks to energy and nutrients among them. METHODS: The present study used data from "China Health and Nutrition Health" where a multistage stratified cluster design was employed to select a stratified probability sample. A total of 12 523 female participants aged 18-49 years old who participated in surveys conducted in 2004-2015 with completed data of demographic characteristics and dietary measurementswere selectedas subjects. There were 2376, 2149, 2142, 2844 and 3012 subjects in waves of 2004, 2006, 2009, 2011, and 2015, respectively. Multivariate Logistic regression model was used to analyze the relationship between socioeconomic factors and snack consumption. Generalized linear model was used to analyze the energy and nutrient intake of snack consumers and non-snack consumers, as well as the contribution of snacks to energy and nutrients. RESULTS: The consumption rate of snacking for women aged 18 to 49 years old had an increasing trend over time(P<0.05), and the rate was 14.24% in 2015, 3.5 times as high as that in 2004. Participants aged 18 to 29 years old whose snake consumption rates were relatively higher compared to those of other aged groups in general waves; also, female adults from the higher education group, the higher yearly income group, and the higher urbanicity index group, and those with the history of smoking or the alcohol use tended to consumed snacks. The change of the influential factors in relation to the consumption of the participant's snack was observed, and age, income level, education level, living area, and the behavior of smoking and drinking were all important factors of snacking. The daily energy and nutrient intake of female snack consumers aged 18 to 49 years old was higher than that of non-snack consumers. The contribution rate of snacks to energy and nutrients varies significantly between survey years; and the contribution of snacks to energy and main nutrients was more than 20% in 2011. CONCLUSION: Snacks have become an important part of the diet of Chinese women aged 18 to 49 years old. Future health promotion programs should be targeted on nutrition education and intervention to guide a reasonable diet structure.