An increase in visceral fat is associated with an increase in insulin resistance, so reducing body fat mass through exercise may help alleviate type 2 diabetes mellitus (T2DM). The current meta-analysis evaluated the effect of changes in body fat via an intervention of regular exercise on hemoglobin A1c (HbA_1c) in patients with T2DM. The inclusion criteria were randomized controlled trials involving adults with T2DM, intervention involving exercise alone, an overall duration of intervention ≥12 weeks, and reporting HbA_1c and body fat mass. The mean differences (MDs) were defined as the MD between the exercise group and the control group, and the MDs in HbA_1c (in percentage) and body fat mass (in kilograms) were calculated. All MDs in HbA_1c were pooled as overall effects. A meta-regression analysis was performed to evaluate the relationship between the MD in the body fat mass (in kilograms) and the MD in HbA_1c. Twenty studies (1,134 subjects) were analyzed. The pooled MD in HbA_1c (in percentage) decreased significantly (−0.4; 95% confidence interval [−0.5, −0.3]) but contained significant heterogeneity (Q = 52.7, p < .01; I² = 41.6%). A meta-regression analysis showed that a decrease in the MD in body fat mass was significantly associated with a decrease in the MD in HbA_1c (R² = 80.0%) and heterogeneity decreased (Q = 27.3, p = .61; I² = 11.9%), and a reduction in body fat mass of 1 kg was estimated to decrease the HbA_1c (%) by approximately 0.2. The current study suggested that a decrease in HbA_1c due to regular exercise depends on a reduction in body fat mass in patients with T2DM.

内脏脂肪的增加与胰岛素抵抗的增加有关，因此通过运动减少体内脂肪量可能有助于缓解 2 型糖尿病 (T2DM)。当前的荟萃分析评估了通过定期运动干预来改变体脂变化对T2DM 患者糖化血红蛋白 (HbA _{1c ) 的影响。}纳入标准是随机对照试验，涉及成人 T2DM、仅涉及运动的干预、干预总持续时间≥12 周，并报告 HbA _1c和体脂量。平均差（MD）定义为运动组和对照组之间的MD，并计算HbA _1c（百分比）和体脂肪量（千克）的MD。所有 MD 的 HbA1c_值汇总为总体效果。进行元回归分析以评估体脂量（千克）MD 与 HbA _1c MD 之间的关系。分析了 20 项研究（1,134 名受试者）。_{HbA 1c}的汇总 MD （百分比）显着下降（−0.4；95% 置信区间 [−0.5，−0.3]），但存在显着异质性（Q  = 52.7，p  < .01；I ²  = 41.6%）。荟萃回归分析表明，体脂量 MD 的降低与 HbA _1c MD 的降低显着相关（R ²  = 80.0%），并且异质性降低（Q  = 27.3，p = .61；I ²  = 11.9%），体脂量每减少 1 kg，估计 HbA _1c (%) 就会降低约 0.2。_{目前的研究表明，定期运动导致的 HbA 1c}降低取决于 T2DM 患者体内脂肪量的减少。