内蒙古地区血清维生素D水平及甲状旁腺激素与2型糖尿病发病的相关性研究

Study on the correlation between serum vitamin D level,parathyroid hormone and type 2 diabetes mellitus in Inner Mongolia

目的评估2型糖尿病患者血清维生素D和甲状旁腺素(parathyroid hormone,PTH)与胰岛素抵抗和胰岛β细胞功能的相关性,分析血清维生素D和PTH在2型糖尿病进展中的作用。方法选取2018年1月-2021年1月在内分泌科住院治疗的2型糖尿病患者376例,收集基线资料并测定血生化指标。分为:血清25-羟基维生素缺乏组[25-(OH)D≤20μg/L]220例、不足组[25-(OH)D>20、≤30μg/L]107例、充足组[25-(OH)D>30μg/L]49例;PTH降低组(PTH<25.16 ng/L)31例、正常组(PTH≥25.16、<38.35 ng/L)137例、升高组(PTH≥38.35 ng/L)208例;根据体重指数(body mass index,BMI)分为正常体重组(BMI≥18.5、≤23.9 kg/m2)108例、超重组(BMI≥24、≤27.9 kg/m2)173例、肥胖组(BMI≥28 kg/m2)95例。采用稳态模型(homeostasis model assessment,HOMA)的胰岛素抵抗指数(insulin resistance index,HOMA-IR)及胰岛β细胞功能指数(HOMA-β)进行评估,统计上述相关数据并进行分析。结果血清维生素D水平三组间比较,糖代谢及钙、磷代谢指标比较显示,BMI、空腹胰岛素(fasting insulin,FINS)、空腹血糖(fasting plasma glucose,FPG)、HOMA-IR、血钙和血磷差异均无统计学意义(P均>0.05),维生素D不足组、充足组较缺乏组糖化血红蛋白、PTH低,差异有统计学意义(P均<0.05);PTH水平三组间比较,糖代谢及钙、磷代谢指标比较显示,BMI、FINS、FPG、糖化血红蛋白、HOMA-IR和血钙差异均无统计学意义(P均>0.05),PTH升高组较降低组和正常组血磷低,差异有统计学意义(P=0.000),PTH升高组较降低组维生素D低,差异有统计学意义(P=0.002);BMI水平三组间比较,年龄、血磷差异均有统计学意义(P均<0.05)。对不同民族临床指标分析发现,蒙古族较汉族维生素D水平高,差异有统计学意义(P=0.034)。Spearman相关性分析,维生素D与PTH(r=-0.240,P<0.05)和HOMA-IR(r=-0.092,P=0.026)呈显著负相关,与血钙(r=0.127,P=0.014)呈显著正相关,PTH与血钙(r=-0.159,P=0.002)和血磷(r=-0.208,P=0.000)呈显著负相关,与HOMA-IR(r=0.086,P=0.009)呈显著正相关,正常PTH与维生素D(r=-0.177,P=0.038)呈显著负相关。多元线性回归分析,HOMA-IR和HOMA-β互为保护因素,FPG和FINS均为HOMA-IR和HOMA-β的危险因素。结论维生素D与胰岛素抵抗呈负相关,PTH与胰岛素抵抗呈正相关,提示维生素D和PTH可能是2型糖尿病发病机制的两个影响因素。

Objective To evaluate the correlation of serum vitamin D(VitD)and parathyroid hormone(PTH)with insulin resistance and isletβ-cell function in patients with type 2 diabetes mellitus(T2DM),and to analyze the role of serum VitD and PTH in the progression of T2DM.Methods A total of 376 T2DM patients hospitalized in endocrinology department from January 2018 to January 2021 were selected.The baseline data were collected and the biochemical indexes were determined.Patients were divided into 3 groups according to serum VitD level,including 220 cases in deficiency group[25-(OH)D≤20μg/L],107 cases in insufficiency group[25-(OH)D>20 and≤30μg/L]and 49 cases in sufficiency group[25-(OH)D>30μg/L].Meanwhile,31 of the patients were classified into PTH decreased group(PTH<25.16 ng/L),137 into normal PTH group(PTH≥25.16 and<38.35 ng/L)and 208 into PTH elevated group(PTH≥38.35 ng/L).According to body mass index(BMI),patients were divided into normal weight group(18.5 kg/m2≤BMI≤23.9 kg/m2),overweight group(BMI≥24 and≤27.9 kg/m2)and obese group(BMI≥28 kg/m2).Results Among the three groups defined by serum VitD level,comparisons of glucose metabolism and calcium and phosphorus metabolism indicators showed no significant differences in BMI,fasting insulin(FINS),fasting plasma glucose(FPG),homeostasis model assessment of insulin resistance index(HOMA-IR),serum calcium and phosphorus(all P>0.05).The levels of glycated hemoglobin(HbA1c)and PTH in vitamin D deficiency group and sufficiency group were significantly lower compared with vitamin D deficiency group(both P<0.05).Among the three groups defined by PTH level,there were no significant differences in BMI,FINS,FPG,HbAlc,HOMA-IR,and serum calcium(all P>0.05).Serum phosphorus in the PTH elevated group was significantly lower compared with PTH decreased and normal PTH group(P=0.000),and VitD in the PTH elevated group was significantly lower compared with PTH decreased group(P=0.002).There were significant differences in age and blood phosphorus among the three groups defined by BMI level(all P<0.05).According to the analysis of clinical indexes of different nationalities,the level of VitD in Mongolians was significantly higher than that in Han nationality patients(P<0.034).Spearman correlation analysis showed that VitD was negatively correlated with PTH and HOMA-IR and positively correlated with serum calcium.PTH was negatively correlated with serum calcium and phosphorus,and positively correlated with HOMA-IR.There was a significant negative correlation between normal PTH and VitD.Multiple linear regression analysis showed that HOMA-IR and homeostasis model assessment ofβ-cell function(HOMA-β)were protective factors,and FPG and FINS were risk factors for HOMA-IR and HOMA-β.Conclusion There is a negative correlation between VitD and insulin resistance,and a positive correlation between PTH and insulin resistance,suggesting that VitD and PTH are possibly two impacting factors for T2DM pathogenesis.