Aim The aim of this study was to investigate the association between serum uric acid (SUA) levels and four insulin resistance surrogates in patients with type 2 diabetes (T2DM). The four non-insulin-based indexes of insulin resistance (IR) include the glucose and triglycerides index (TyG), TyG index with body mass index (TyG-BMI), ratio of triglycerides to high-density lipoprotein cholesterol (TG/HDL-c) and metabolic score for insulin resistance (METS-IR). Methods A total of 687 patients with T2DM were enrolled in the current study. Patients were stratified into three groups according to their levels of SUA. Spearman correlation was used to analyze the correlation between SUA and clinical variables. Multiple linear regression analysis was used to assess the association between SUA and the four insulin resistance surrogates. Receiver operating characteristic (ROC) analyses and the area under the ROC curve (AUC) were then used to assess the ability of TyG, TyG-BMI, TG/HDL-c, and METS-IR to discriminate hyperuricemia (HUA) in T2DM. Results SUA in T2DM was significantly positively correlated with TyG (r 0.406 P < 0.01), TyG-BMI (r 0.272 P < 0.01), TG/HDL-c (r 0.493 P < 0.01), and METS-IR (r 0.238 P < 0.01). Furthermore, higher values of the four insulin resistance surrogates were independently correlated with higher SUA levels in T2DM patients (P < 0.01 for all) after adjusting for confounding factors. TyG, TyG-BMI, TG/HDL-c, and METS-IR all had a significant discriminative ability for HUA in patients with T2DM. The AUC values were 0.693 (95% CI 0.645–0.741), 0.649 (95% CI 0.599–0.699), 0.768 (95% CI 0.726–0.811), and 0.660 (95% CI 0.609–0.710), respectively. Conclusion The present study suggests that TyG, TyG-BMI, TG/HDL-c and METS-IR had a significant correlation with SUA in T2DM. TG/HDL-c was the best marker among the four insulin resistance surrogates for the identification of HUA in T2DM.

The patient in the present case report, a 27-year-old man, was diagnosed with Graves' disease and hypokalemia. The patient was treated with methimazole and intermittent potassium supplementation. Following treatment, the patient was still suffering from fatigue, accompanied by palpitations, a hand tremor, fear of heat and sweating. Hypoglycemia was revealed by monitoring fingertip blood glucose levels. The laboratory investigations indicated that serum insulin levels were significantly elevated (>1,000 µIU/ml), the test for serum insulin autoantibody (IAA) was positive, and insulin autoimmune syndrome (IAS) was diagnosed. Following symptomatic treatment, the patients insulin levels decreased, and the hypoglycemia episode was gradually relieved. Hypoglycemia may be prone to missed diagnosis in patients with Graves' disease and hypokalemic periodic paralysis. Monitoring fingertip blood glucose level is a convenient and feasible method to detect hypoglycemia. Furthermore, serum insulin and IAA detection should be assessed to exclude or confirm IAS.

Primary aldosteronism (PA) is a well-documented cause of secondary hypertension, often accompanied by hypokalemia. However, PA with normal blood pressure and hypokalemic rhabdomyolysis (RM) is rare. We report a case of hypokalemia-induced RM as the first symptom of PA. A 65-year-old woman was admitted due to intermittent limb weakness and myalgia. She denied a history of hypertension.Laboratory findings showed profound hypokalemia (1.8 mmol/L) and extreme elevation of creatinine kinase (CK) levels (18,370 U/L), suggestive of hypokalemia-induced RM. She was administered intravenous fluids as well as active oral and intravenous potassium supplements. CK and myoglobin levels gradually decreased, but the serum potassium recovery was poor. Further evaluations strongly suggested PA by an aldosteroneproducing adenoma, which was surgically removed. After surgery, the patient recovered well. The systolic blood pressure decreased by approximately 10-20 mmHg and the diastolic blood pressure decreased by approximately 5-10 mmHg. After discontinuation of spironolactone and oral potassium supplementation, the patient had normal serum potassium levels. This case indicates that PA is a cause of hypokalemic RM, even in patients with normal blood pressure. In addition, attention should be paid to changes in serum aminotransferase levels associated with RM. If the patient had no liver disease, it might be a marker for skeletal muscle injury instead of hepatocyte damage.