Why do men have worse COVID-19-related outcomes? A systematic review and meta-analysis with sex adjusted for age

We aimed to study the mechanism behind worse coronavirus disease-19 (COVID-19) outcomes in men and whether the differences between sexes regarding mortality as well as disease severity are influenced by sex hormones. To do so, we used age as a covariate in the meta-regression and subgroup analyses. This was a systematic search and meta-analysis of observational cohorts reporting COVID-19 outcomes. The PubMed (Medline) and Cochrane Library databases were searched. The primary outcome was COVID-19-associated mortality and the secondary outcome was COVID-19 severity. The study was registered at PROSPERO: 42020182924. For mortality, men had a relative risk of 1.36 (95%CI: 1.17 to 1.59; I2 63%, P for heterogeneity <0.01) compared to women. Age was not a significant covariate in meta-analysis heterogeneity (P=0.393) or subgroup analysis. For disease severity, being male was associated with a relative risk of 1.29 (95%CI: 1.19 to 1.40; I2 48%, P for heterogeneity <0.01) compared to the relative risk of women. Again, age did not influence the outcomes of the meta-regression (P=0.914) or subgroup analysis. Men had a higher risk of COVID-19 mortality and severity regardless of age, decreasing the odds of hormonal influences in the described outcomes.

Effect of metabolic syndrome and of its individual components on renal function of patients with type 2 diabetes mellitus

The objective of this study was to evaluate the effect of metabolic syndrome (MetS) and its individual components on the renal function of patients with type 2 diabetes mellitus (DM). A cross-sectional study was performed in 842 type 2 DM patients. A clinical and laboratory evaluation, including estimated glomerular filtration rate (eGFR) calculated by the modification of diet in renal disease formula, was performed. MetS was defined according to National Cholesterol Education Program - Adult Treatment Panel III criteria. Mean patient age was 57.9 ± 10.1 years and 313 (37.2 percent) patients were males. MetS was detected in 662 (78.6 percent) patients. A progressive reduction in eGFR was observed as the number of individual MetS components increased (one: 98.2 ± 30.8; two: 92.9 ± 28.1; three: 84.0 ± 25.1; four: 83.8 ± 28.5, and five: 79.0 ± 23.0; P < 0.001). MetS increased the risk for low eGFR (<60 mL·min-1·1.73 (m²)-1) 2.82-fold (95 percentCI = 1.55-5.12, P < 0.001). Hypertension (OR = 2.2, 95 percentCI = 1.39-3.49, P = 0.001) and hypertriglyceridemia (OR = 1.62, 95 percentCI = 1.19-2.20, P = 0.002) were the individual components with the strongest associations with low eGFR. In conclusion, there is an association between MetS and the reduction of eGFR in patients with type 2 DM, with hypertension and hypertriglyceridemia being the most important contributors in this sample. Interventional studies should be conducted to determine if treatment of MetS can prevent renal failure in type 2 DM patients.

The prevalence of chronic diabetic complications and metabolic syndrome is not associated with maternal type 2 diabetes

The maternal history of type 2 diabetes mellitus (DM) has been reported more frequently in patients with type 2 DM than paternal history. The aim of the present study was to determine if there was an association between maternal history of DM and the presence of chronic complications or metabolic syndrome (MetS) in patients with type 2 DM. A cross-sectional study was conducted with 1455 patients with type 2 DM. All outpatients with type 2 diabetes attending the endocrine clinics who fulfilled the eligibility criteria were included. Familial history of DM was determined with a questionnaire. Diabetic complications were assessed using standard procedures. The definition of MetS used was that of the World Health Organization and the National Cholesterol Education Program's Adult Treatment Panel III report criteria. Maternal history of DM was present in 469 (32.3 percent), absent in 713 (49.1 percent) and unknown in 273 patients (18.7 percent). Paternal history of DM was positive in 255 (17.6 percent), negative in 927 (63.8 percent) and unknown in 235 patients (16.1 percent). The frequency of microvascular chronic complications in patients with and without a positive maternal history of DM was similar: diabetic nephropathy (51.5 vs 52.5 percent), diabetic retinopathy (46.0 vs 41.7 percent), and diabetic sensory neuropathy (31.0 vs 37.1 percent). The prevalence of macrovascular chronic complications and MetS was also similar. Patients with type 2 DM were more likely to have a maternal than a paternal history of DM, although maternal history of DM was not associated with an increased prevalence of chronic complications or MetS.

Diabetic retinopathy is associated with early autonomic dysfunction assessed by exercise-related heart rate changes

Diabetic retinopathy has been associated with cardiac autonomic dysfunction in both type 1 and type 2 diabetes mellitus (DM) patients. Heart rate (HR) changes during exercise testing indicate early alterations in autonomous tonus. The aim of the present study was to investigate the association of diabetic retinopathy with exercise-related HR changes. A cross-sectional study was performed on 72 type 2 and 40 type 1 DM patients. Autonomic dysfunction was assessed by exercise-related HR changes (Bruce protocol). The maximum HR increase, defined as the difference between the peak exercise rate and the resting rate at baseline, and HR recovery, defined as the reduction in HR from the peak exercise to the HR at 1, 2, and 4 min after the cessation of the exercise, were determined. In type 2 DM patients, lower maximum HR increase (OR = 1.62, 95 percentCI = 1.03-2.54; P = 0.036), lower HR recovery at 2 (OR = 2.04, 95 percentCI = 1.16-3.57; P = 0.012) and 4 min (OR = 2.67, 95 percentCI = 1.37-5.20; P = 0.004) were associated with diabetic retinopathy, adjusted for confounding factors. In type 1 DM, the absence of an increase in HR at intervals of 10 bpm each during exercise added 100 percent to the odds for diabetic retinopathy (OR = 2.01, 95 percentCI = 1.1-3.69; P = 0.02) when adjusted for DM duration, A1c test and diastolic blood pressure. In conclusion, early autonomic dysfunction was associated with diabetic retinopathy. The recognition of HR changes during exercise can be used to identify a high-risk group for diabetic retinopathy.