Calcium deficiency affects serum glucose and lipids by inhibiting PGC-1α expression in skeletal muscle of rats

Objective The present study was aimed to investigate the effects of calcium deficiency on blood glucose and lipids of rats. Methods Following one week of adaptation, 20 male SD rats (7 weeks old) were randomly assigned into two groups: 10 were control group (0.5% calcium in feed) and 10 were calcium deficiency group (0.15% calcium in feed). Food intake was measured daily, and body weight was measured weekly. After 16 weeks, the rats were anesthetized with pentobarbital via intraperitoneal injection. The blood samples were obtained to examine serum glucose (GLU), total cholesterol (TC), triglyceride (TG), low density lipoprotein cholesterol (LDL-C) and high density lipoprotein cholesterol (HDL-C). The mRNA and protein levels of PGC-1α were detected in skeletal muscles. The association between the expression of PGC-1α and blood glucose and lipids levels were analyzed by Pearson's correlation. Results Compared with the control group, food intake and body weight of rats were not significantly different in calcium deficiency group (all P>0.05), while the levels of serum GLU, TC, LDL-C were increased; although the levels of TG and HDL-C were not significantly different between the two groups of animals, a rising tendency was detected; the ratio of HDL-C to LDL-C was decreased (all P<0.05). The mRNA and protein expression of proliferator-activated receptor γ coactivator-1α (PGC-1α), one of the key factors for regulation of glucose and lipid metabolism and mitochondrial function in skeletal muscle, were decreased in rats from calcium deficiency group (all P<0.05). There was an obvious negative correlation between PGC-1α expressions and serum TC and LDL-C (all P<0.05). Conclusions Calcium deficiency did not affect the body weight of rats, but it could induce serum glucose and lipids disorder through inhibiting the expression of PGC-1α in skeletal muscle.