Facultad de Ciencias de la Salud

Background. Very few studies have analyzed early histologic lesions of diabetic nephropathy (DN) in patients without signs of clinical involvement (microalbuminuria). In this study, we analyzed renal histologic lesions in necropsies of diabetic patients with or without previous signs of DN. Methods. Histological material was analyzed from 21 autopsies of type 2 diabetes mellitus (T2DM) patients (9 with albuminuria and 12 without albuminuria) and 4 controls. Histologic lesions were evaluated according to the Tervaert classification. Results. Kidneys of diabetic patients presented significantly higher scores in most histologic indices analyzed (glomerular basal membrane thickening, mild and severe mesangial expansion, nodular sclerosis, interstitial fibrosis, and tubular atrophy) than in nondiabetic controls (p < 0:01 in all cases). In contrast, no significant differences were detected between histologic scores when comparing the 21 diabetic patients with and without albuminuria. A significant percentage of cases without albuminuria showed moderate to severe histologic lesions, particularly severe mesangial expansion and severe glomerular vascular lesions. No significant differences were found in age, blood pressure, diabetes vintage, BMI, HbA1c, cholesterol, triglycerides, or treatments between the two (albuminuric vs. nonalbuminuric) T2DM patient groups. Conclusions. Our data suggest that histologic lesions of DN are present in the early stages of the disease, even without albuminuria presence. More precise and earlier metabolic control is recommended in T2DM, and monitoring of risk factors can play a role in DN development.

Introduction. Renal function and thyroid metabolism are tightly related. However, evidence about subclinical hypothyroidism prevalence in patients with chronic kidney disease and its related factors is scarce. Objectives. Our aim is to analyze subclinical hypothyroidism prevalence and its related factors in patients with advanced chronic kidney disease. Materials and methods. Nondialysis-dependent patients with chronic kidney disease at stages 3 to 5 were included. Other inclusion criteria were age above 18 years and clinical stability. Patients with diagnosed thyroid illnesses were excluded. Subclinical hypothyroidism was de ned as thyroid stimulating hormone (TSH) > 5.3 mU/L, with free thyroxine 4 (FT4) between 0.54 and 1.24 ng/dl. Filiation data, comorbidities, and routine blood and urine test results were registered. Results. A total of 299 patients were included. Of them, 184 (61.5%) were men. The mean age was 71 ± 13 years old. The mean glomerular fltration rate (CKD-EPI) was 22 ± 9 ml/min/ 1.73m2. According to chronic kidney disease stages, global distribution of patients was as follows: Stage 3, 67 patients (22.4%); Stage 4, 155 patients (51.8%); and Stage 5, 77 patients (25.8%). We found subclinical hypothyroidism in 54 (18.1%) patients. According to chronic kidney disease stages, distribution of affected patients was as follows: Stage 3, 9 patients (13%); Stage 4, 25 patients (16.1%); and Stage 5, 20 patients (26%). Di¤erences among stages were statistically signifcant. By univariate analysis, factors related with subclinical hypothyroidism were as follows: age RR 1.048 (95% CI 1.019–1.078; p = 0.001), hypertension RR 2.705 (95% CI 1.026–7.130; p = 0.04), glomerular fltration rate RR 0.962 (95% CI 0.929–0.996; p = 0.03), and proteinuria higher than 1 gram/day RR 2.387 (95% CI 1.303–4.374; p = 0.005). By multivariate analysis adjusted by age, hypertension, glomerular fltration rate, proteinuria, diabetes, and cardiovascular disease history, only age RR 1.016 (95% CI 1.009–1.028; p = 0.04) and glomerular fltration rate RR 0.963 (95% CI 0.930–0.997; p = 0.03) preserved their independent association with subclinical hypothyroidism. Conclusions. Subclinical hypothyroidism prevalence in patients with chronic kidney disease is high and increases with renal disease severity. Factors independently related to subclinical hypothyroidism are age and glomerular fltration rate.