Cardiac electrophysiology, structure and diastolic function in patients with diabetic foot versus those without diabetic foot.

AIMS/INTRODUCTION: To evaluate the differences in cardiac autonomic function, cardiac structure and diastolic function between individuals with diabetic foot (DF) and those with diabetes but without DF. MATERIALS AND METHODS: A total of 413 individuals with DF and 437 without DF who underwent a 24-h electrocardiogram Holter and a Doppler echocardiogram were included. The heart rate variability parameters to evaluate cardiac autonomic function, and the indices for the assessment of cardiac structure and left ventricular (LV) diastolic function, including left atrium, LV posterior wall thickness, interventricular septum and E/e' ratio, were measured or calculated. Propensity score matching was used for the sensitivity analysis to minimize potential imbalance. RESULTS: In both the crude and propensity score matching analyses, significant differences were observed in heart rate variability between individuals with and without DF, as evidenced by lower standard deviation of the normal sinus interval, lower low-frequency power/high-frequency power ratio, lower standard deviation of the 5-min average RR intervals, lower low-frequency power, lower percentage of normal adjacent RR interval difference >50 ms, lower root mean square of successive RR interval differences and lower high-frequency power (all P < 0.05). In multivariate analysis, DF showed an independent negative correlation with the aforementioned indices of heart rate variability (all P < 0.05). Individuals with DF showed higher left atrium, LV posterior wall thickness, interventricular septum and a higher E/e' ratio than those without DF in the crude analysis (all P < 0.05), whereas these indices were no longer associated with DF in the multivariate analysis and the propensity score matching analyses. CONCLUSIONS: Cardiac autonomic modulation was more severely impaired in individuals with DF than in their counterparts without DF. There has been insufficient evidence to demonstrate the independent association of DF and LV diastolic dysfunction.

Association of parameters of nocturnal hypoxemia with diabetic microvascular complications: A cross-sectional study.

AIMS: To examine the association between obstructive sleep apnea (OSA)-related nocturnal hypoxemia parameters and diabetic microvascular complications in patients with type 2 diabetes mellitus (T2DM). METHODS: A total of 463 Chinese patients with T2DM underwent overnight polysomnography, followed by diagnosis of diabetic microvascular complications including diabetic peripheral neuropathy (DPN), diabetic retinopathy (DR) and diabetic nephropathy (DN). Parameters of nocturnal hypoxemia, including apnea-hypopnea index (AHI), oxygen desaturation index (ODI), time spent with SpO2 < 90% (T90%) or <85% (T85%), mean SpO2 and lowest SpO2, were recorded. RESULTS: AHI was independently associated with higher odds of DPN (OR 1.19; 95% CI, 1.05-1.36; P = 0.008) after adjustment for possible confounders. Moreover, patients with severe OSA (AHI ≥ 30 events/h) had higher likelihood of having DPN than those with mild OSA (OR 2.36; 95% CI, 1.31-4.25; P = 0.004). When combining DPN, DR and DN into an overall diabetic microvascular complication index, AHI was also independently associated with higher odds of having any diabetic microvascular complication (OR 1.21; 95% CI, 1.06-1.38; P = 0.006). CONCLUSIONS: The AHI may be the OSA-related index that most strongly reflects the association of OSA and diabetic microvascular complications, compared with other OSA-related hypoxemia parameters.

Vitamin D and Incidence of Prediabetes or Type 2 Diabetes: A Four-Year Follow-Up Community-Based Study.

AIM: To examine whether the baseline 25-hydroxyvitamin D [25(OH)D] level was predictive of the onset of prediabetes or type 2 diabetes (T2DM) in the Chinese population. METHODS: This was a 4-year follow-up study that was conducted in the Chengdu region of China as part of the China National Diabetes and Metabolic Disorders Study. The study included 490 participants that were free of prediabetes and type 2 diabetes mellitus (T2DM) at baseline and had complete data by follow-up examinations. Glucose, insulin, and 25(OH)D levels were measured at baseline and at 4 years later. Prediabetes and T2DM were defined by results obtained from an oral glucose tolerance test. RESULTS: Over a 4-year follow-up, 95 (48.5‰) developed prediabetes and 31 (15.8‰) individuals developed diabetes. Low 25(OH)D status was significantly associated with the risk of developing prediabetes [OR 3.01 (95% CI: 1.50-6.06), P = 0.002] and T2DM [OR 5.61 (95% CI: 1.73-18.27), P = 0.004] after adjustment for multiple potential confounders. In a multiple linear regression analysis, low baseline levels of 25(OH)D were an independent predictor of increased insulin resistance over a 4-year period (P < 0.05). CONCLUSIONS: The current prospective study suggests that low 25(OH)D levels might have contributed to the incidence of prediabetes or T2DM in Chinese individuals. This trial is registered with TR-CCH-ChiCTR-OCS-09000361.