This study investigated the relationship strength between hypothyroidism and cardiovascular and renal outcomes in diabetic patients. The electronic databases PubMed, EmBase, and Cochrane library were screened for relevant studies published before November 2018. The outcomes included major cardiovascular events (MACEs), all-cause mortality, cardiac death, stroke, diabetic nephropathy (DN), diabetic retinopathy (DR), and chronic kidney disease (CKD). The pooled results for all outcomes were calculated using random-effects models. A total of eight studies met the inclusion criteria. The summary results indicated that hypothyroidism was not associated with the risk of MACEs (OR:1.21; 95%CI:0.68-2.16; = 0.514), all-cause mortality (OR:1.27; 95%CI:0.93-1.74; = 0.136), cardiac death (OR:1.16; 95%CI:0.89-1.52; = 0.271), stroke (OR:0.96; 95%CI: 0.49-1.88; = 0.915), and DN (OR:1.71; 95%CI:0.37-7.90; = 0.490). There was a significant association between hypothyroidism and the risk of DR (OR:1.73; 95%CI:1.08-2.77; = 0.023) and CKD (OR:1.22; 95%CI:1.10-1.36; < 0.001). These findings indicate that diabetic patients with hypothyroidism have an increased risk of DR and CKD. Additional large-scale prospective studies should be carried out to verify the prognosis of patients with diabetes and hypothyroidism.
Copyright © 2020 Zhang, Feng, Kang, Guo, Ti, Hao, Gao and Gao.