Abdo Basheer, Abdullah Mohammed, AlShoaibi Ismaeel A, Ahmed Faisal, Alawdi Redwan, Alzanen Khaled, Algaadi Kamal
Department of Internal Medicine, School of Medicine, Ibb University, Ibb, YEM.
Department of Urology, Ibb University, Ibb, YEM.
Cureus. 2024 Jun 16;16(6):e62468. doi: 10.7759/cureus.62468. eCollection 2024 Jun.
Significant links between low serum levels of vitamin D3 and insufficient glycemic control in patients with type 2 diabetes mellitus (T2DM) have been reported previously in the literature. However, there is no exciting evidence on the association between glycated hemoglobin (HbA1c) and vitamin D levels in T2DM individuals in our nation (Yemen). This study aimed to investigate the relationship between HbA1c and vitamin D levels in T2DM patients in a resource-limited setting.
A retrospective cross-sectional study was conducted at the Al-Raffa Center, Ibb, Yemen between June 2018 and September 2023 including 396 patients diagnosed with T2DM. The patient characteristics, comorbidities, HbA1c, and vitamin D levels were gathered from patients' medical profiles. Linear regression analysis was used to find the factors associated with vitamin D deficiency (serum 25(OH)D levels < 20 ng/mL) among T2DM patients. Subsequently, the correlation between HbA1c and vitamin D levels was examined using receiver operating characteristic (ROC) curve analysis.
The mean age was 44.6 ±14.6 years and most of them (n= 227, 57.3%) were female and from a rural area (n= 229, 57.8%). Comorbidities were hypertension, dyslipidemia disease, and cardiovascular disease in 176 (44.4%), 63 (15.9%), and 88 (22.2%) cases, respectively. The mean HbA1c was 8.1 ±2.5%. The mean vitamin D level was 26.9 ±16.5 ng/mL and low vitamin D was present in 260 (65.7%) (vitamin D deficiency in 160 (40.4%) and vitamin D insufficiency in 100 (25.3%) cases). In regression analysis, obesity (>30 kg/m) (odds ratio (OR): 299.49; 95% confidence interval (CI): 72.66 - 1234.42, p <0.0001), higher HbA1c levels (OR: 1.61; 95% CI: 1.26 - 2.05, p =0.0001), and urban residence (OR: 23.98; 95% CI: 5.62 - 102.42, p <0.0001) were associated with vitamin D deficiency. There was a negative correlation between the vitamin D level and HbA1c which was statistically significant (correlation coefficient r: -0.5452; 95% CI: -0.6109 to -0.4720, p <0.0001). Using the ROC analysis, the serum vitamin D value of ≤18.42 ng/ml was the best cut-off point to predict hyperglycemia (area under the curve: 0.633, 95% CI: 0.672 to 0.770, sensitivity: 52%, specificity: 84.71 %, Yoden's index: 0.3671, p <0.001). Based on this cut-off, 39.4% of individuals (37.5% in the normoglycemic group and 90.9% in the hyperglycemic group) were vitamin D deficient.
In this study, low vitamin D was common among T2DM patients, especially those with poor glycemic control. We observed a link between HbA1c levels, urban residency, and BMI with vitamin D deficiency in T2DM patients. The association was distinguished by low vitamin D levels and elevated HbA1c. Additionally, we found that the serum vitamin D value of ≤18.42 ng/ml was the best cut-off point to predict hyperglycemia in T2DM patients with moderate agreement. To manage their disease, patients with T2DM should take their medications as prescribed and live a healthy lifestyle. This will increase their overall health, especially their vitamin D levels.
此前文献报道，2型糖尿病（T2DM）患者血清维生素D3水平低与血糖控制不佳之间存在显著关联。然而，在我国（也门），尚无关于T2DM患者糖化血红蛋白（HbA1c）与维生素D水平之间关联的令人振奋的证据。本研究旨在调查资源有限环境下T2DM患者中HbA1c与维生素D水平之间的关系。
2018年6月至2023年9月在也门伊卜省的拉菲中心开展了一项回顾性横断面研究，纳入396例确诊为T2DM的患者。从患者的病历中收集患者特征、合并症、HbA1c和维生素D水平。采用线性回归分析确定T2DM患者中与维生素D缺乏（血清25(OH)D水平<20 ng/mL）相关的因素。随后，使用受试者工作特征（ROC）曲线分析检查HbA1c与维生素D水平之间的相关性。
平均年龄为44.6±14.6岁，其中大多数（n = 227，57.3%）为女性，且来自农村地区（n = 229，57.8%）。合并症分别为高血压、血脂异常和心血管疾病，各有176例（44.4%）、63例（15.9%）和88例（22.2%）。平均HbA1c为8.1±2.5%。平均维生素D水平为26.9±16.5 ng/mL，260例（65.7%）存在低维生素D情况（160例（40.4%）为维生素D缺乏，100例（25.3%）为维生素D不足）。回归分析显示，肥胖（>30 kg/m²）（比值比（OR）：299.49；95%置信区间（CI）：72.66 - 1234.42，p<0.0001）、较高的HbA1c水平（OR：1.61；95%CI：1.26 - 2.05，p = 0.0001）和城市居住（OR：23.98；95%CI：5.62 - 102.42，p<0.0001）与维生素D缺乏相关。维生素D水平与HbA1c之间存在负相关，具有统计学意义（相关系数r：-0.5452；95%CI：-0.6109至-0.4720，p<0.0001）。采用ROC分析，血清维生素D值≤18.42 ng/ml是预测高血糖的最佳切点（曲线下面积：0.633，95%CI：0.672至0.770，敏感性：52%，特异性：84.71%，约登指数：0.3671，p<0.001）。基于此切点，39.4%的个体（血糖正常组为37.5%，高血糖组为90.9%）存在维生素D缺乏。
在本研究中，低维生素D在T2DM患者中很常见，尤其是血糖控制不佳的患者。我们观察到T2DM患者的HbA1c水平、城市居住情况和BMI与维生素D缺乏之间存在关联。这种关联表现为低维生素D水平和升高的HbA1c。此外，我们发现血清维生素D值≤18.42 ng/ml是预测T2DM患者高血糖的最佳切点，一致性中等。为控制病情，T2DM患者应按医嘱服药并保持健康的生活方式。这将改善他们的整体健康状况，尤其是提高他们的维生素D水平。
