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

Abstract

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.

U-shaped association of serum magnesium with mild cognitive impairment among hemodialysis patients: a multicenter study

“…Although the disparity in the study population, in accordance with our results, several previous studies have observed the U-shaped association between magnesium levels and other chronic inflammatory conditions [ 25–29 ]. A prospective study containing 5044 Chinese adults showed a U-shaped association between serum magnesium level and insulin resistance, and type 2 diabetes, with low and high levels associated with increased risk [ 25 ]. Yue et al.…”

Association of serum magnesium with metabolic syndrome and the role of chronic kidney disease: A population‐based cohort study with Mendelian randomization

“…We found the inverse association of serum magnesium with MetS and elevated fasting glucose to be nonlinear, indicating that potential protective effects of high magnesium levels remain stable after a certain threshold. In line with this, a prospective cohort study in 5044 participants demonstrated a nonlinear relationship of serum magnesium with diabetes and insulin resistance 47 . On the other hand, Negrea et al found that serum magnesium <1.9 mg/dL and >2.1 mg/dL was associated with all‐cause mortality in a large cohort of patients with CKD 48 …”

“…In line with this, a prospective cohort study in 5044 participants demonstrated a nonlinear relationship of serum magnesium with diabetes and insulin resistance. 47 On the other hand, Negrea et al found that serum magnesium <1.9 mg/dL and >2.1 mg/ dL was associated with all-cause mortality in a large cohort of patients with CKD. 48 The observed lack of longitudinal association between serum magnesium and MetS in our study was unexpected, given a-albeit weak-causal relation.…”

Magnesium deficiency as a contributing factor to type 2 diabetes: a review of the literature

“…Interestingly, in people with type 2 diabetes, plasma magnesium level was conversely associated with markers of insulin resistance, showing that lower magnesium is related to more insulin resistance. This finding suggests that magnesium supplementation may have therapeutic effects in reducing insulin resistance in the liver, muscle, and pancreas with different mechanisms (9,10). In that way, magnesium deficiency appears to take a significant part in insulin resistance and glucose handling.…”