Association Between Blood Calcium, Magnesium, and Non-alcoholic Fatty Liver Disease in Adults: a Cohort-Based Case-Control Study

Previous studies have shown that calcium (Ca), magnesium (Mg), and Ca/Mg ratio are associated with inflammation and metabolic disorders, but their relationship with non-alcoholic fatty liver disease (NAFLD) is unclear. Thus, we aimed to explore the association between Ca, Mg, Ca/Mg ratio, and NAFLD in Chinese adults. We conducted a case-control study based on the Kailuan Cohort in China, including 1816 cases and 1111 gender- and age-matched controls. Dose-response relationships between blood Ca, Mg, Ca/Mg ratio, and NAFLD were evaluated using restricted cubic splines. Odds ratios (ORs) and their 95% confidence intervals (CIs) were estimated by logistic regression models. A negative association between blood Ca (overall association P < 0.001 and linear association P < 0.001) and NAFLD as well as Ca/Mg ratio (overall association P = 0.002 and linear association P = 0.024) and NAFLD was observed. Compared with the highest quartile, the adjusted OR (95% CI) for the lowest quartile of Ca and Ca/Mg ratio was 2.116 (1.679-2.667) and 1.358 (1.076-1.713), respectively. A U-shaped relationship was found for blood Mg and NAFLD, with the highest OR of 1.685 in the lowest quartile group when using the second quartile as a reference. Additionally, we observed the interaction between alanine aminotransferase and blood Ca (P = 0.024), total cholesterol (P = 0.017), low-density lipoprotein-cholesterol (P = 0.013), and blood Mg, as well as total cholesterol and Ca/Mg ratio (P = 0.014). Lower blood Ca and Ca/Mg ratio were significantly associated with the risk of NAFLD. Liver function or lipid metabolism parameters may modify their association, suggesting an individualized prevention strategy for NAFLD.

The Association Between Calcium, Magnesium, and Ratio of Calcium/Magnesium in Seminal Plasma and Sperm Quality

The study aimed to examine the relationships between calcium, magnesium, and calcium/magnesium ratio in semen plasma and sperm quality. It was a cross-sectional study based on a program aiming at promoting the reproductive health in less-developed areas. A total of 515 men aged between 18 and 55 years provided semen specimens at family planning clinics in Sandu County, Guizhou Province, China. Total calcium and magnesium concentrations in semen plasma were measured with flame atomic absorption spectrometry. Sperm quality, including sperm motility and concentration, was evaluated by using a computer-assisted sperm analysis method. The medians of seminal plasma calcium, magnesium, and zinc concentrations were 9.61, 4.41, and 2.23 mmol/l, respectively. Calcium concentration and calcium/magnesium ratio were negatively associated with sperm concentrations (β = -0.47, P = 0.0123 for calcium; β = -0.25, P = 0.0393 for calcium/magnesium ratio) after adjusting for zinc and other covariates. In stratified analyses, the association between calcium and sperm concentrations only persisted among subjects with a calcium/magnesium ratio of ≤2.5 (β = -0.71, P = 0.0268). In the same stratum, magnesium was associated with increased sperm concentration (β = 0.73, P = 0.0386). Among subjects with a calcium/magnesium ratio of >2.5, neither calcium nor magnesium was associated with sperm concentration. In conclusion, total calcium and magnesium concentrations were associated with sperm concentration among subjects with a lower calcium/magnesium ratio. The calcium and magnesium ratio had a modifying effect on the associations of calcium and magnesium with sperm concentration.