Mwanza Research Centre, National Institute for Medical Research, Mwanza, Tanzania.
Faculty of Epidemiology and Population Health, London School of Hygiene & Tropical Medicine, London, UK.
Trop Med Int Health. 2021 Apr;26(4):435-443. doi: 10.1111/tmi.13545. Epub 2021 Jan 27.
Studies on phenotypes of diabetes in Africa are inconsistent. We assessed the role of β-cell dysfunction and insulin resistance on pre-diabetes and diabetes.
We included 1890 participants with mean age of 40.6 (SD11.9) years in a cross-sectional study among male and female adults in Tanzania during 2016 to 2017. Data on C-reactive protein (CRP), alpha-acid glycoprotein (AGP), HIV, oral glucose tolerance test (OGTT), body composition and insulin were collected. Insulinogenic index and HOMA-IR were used to derive an overall marker of β-cell dysfunction and insulin resistance which was categorised as follows: normal β-cell function and insulin sensitivity, isolated β-cell dysfunction, isolated insulin resistance, and combined β-cell dysfunction and insulin resistance. Pre-diabetes and diabetes were defined as 2-hour OGTT glucose between 7.8-11.0 and ≥ 11.1 mmol/L, respectively. Multinomial regression assessed the association of β-cell dysfunction and insulin resistance with outcome measures.
β-cell dysfunction, insulin resistance, and combined β-cell dysfunction and insulin resistance were associated with higher pre-diabetes risk. Similarly, isolated β-cell dysfunction (adjusted relative risk ratio (aRRR) 4.8 (95% confidence interval (CI) 2.5, 9.0), isolated insulin resistance (aRRR 3.2 (95% CI 1.5, 6.9), and combined β-cell dysfunction and insulin resistance (aRRR 35.9 (95% CI 17.2, 75.2) were associated with higher diabetes risk. CRP, AGP and HIV were associated with higher diabetes risk, but fat mass was not. 31%, 10% and 33% of diabetes cases were attributed to β-cell dysfunction, insulin resistance, and combined β-cell dysfunction and insulin resistance, respectively.
β-cell dysfunction seemed to explain most of diabetes cases compared to insulin resistance in this population. Cohort studies on evolution of diabetes in Africa are needed to confirm these results.
非洲的糖尿病表型研究结果并不一致。本研究旨在评估β细胞功能障碍和胰岛素抵抗在糖尿病前期和糖尿病中的作用。
本研究纳入了 2016 年至 2017 年期间在坦桑尼亚进行的一项横断面研究中的 1890 名男性和女性成年人，他们的平均年龄为 40.6（11.9）岁。收集了 C 反应蛋白（CRP）、α-酸性糖蛋白（AGP）、人类免疫缺陷病毒（HIV）、口服葡萄糖耐量试验（OGTT）、身体成分和胰岛素的数据。使用胰岛素原指数和 HOMA-IR 来推导β细胞功能障碍和胰岛素抵抗的综合标志物，并将其分为以下几类：正常β细胞功能和胰岛素敏感性、孤立性β细胞功能障碍、孤立性胰岛素抵抗以及β细胞功能障碍和胰岛素抵抗的合并存在。糖尿病前期和糖尿病的定义分别为 2 小时 OGTT 血糖为 7.8-11.0mmol/L 和≥11.1mmol/L。采用多项回归分析评估β细胞功能障碍和胰岛素抵抗与结局指标的相关性。
β细胞功能障碍、胰岛素抵抗以及β细胞功能障碍和胰岛素抵抗的合并存在与更高的糖尿病前期风险相关。同样，孤立性β细胞功能障碍（调整后的相对风险比[aRRR] 4.8（95%置信区间[CI] 2.5, 9.0））、孤立性胰岛素抵抗（aRRR 3.2（95% CI 1.5, 6.9））和β细胞功能障碍和胰岛素抵抗的合并存在（aRRR 35.9（95% CI 17.2, 75.2））与更高的糖尿病风险相关。CRP、AGP 和 HIV 与更高的糖尿病风险相关，但脂肪量与之无关。在该人群中，β细胞功能障碍、胰岛素抵抗和β细胞功能障碍和胰岛素抵抗的合并存在分别解释了 31%、10%和 33%的糖尿病病例。
与胰岛素抵抗相比，β细胞功能障碍似乎可以解释该人群中大多数糖尿病病例。需要进行关于非洲糖尿病演变的队列研究来证实这些结果。
