Non-albumin proteinuria marks tubular involvement and is associated with arterial stiffness in subjects affected by severe obesity

• Published in: Obesity research & clinical practice Vol. 17; no. 6; pp. 485 - 491
• Main Authors: Moriconi, Diego, Nannipieri, Monica, Armenia, Silvia, Taddei, Stefano, Solini, Anna, Bruno, Rosa Maria
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier Ltd 01.11.2023
• Subjects: Albuminuria - etiology; Arterial stiffness; Blood Pressure; Carotid-femoral pulse wave velocity; Cholesterol, LDL; Humans; Non-albumin proteinuria; Obesity - complications; Obesity, Morbid - complications; Obesity, Morbid - surgery; Obesity-related kidney disease; Pulse Wave Analysis - adverse effects; Risk Factors; Tubular proteinuria; Vascular Stiffness - physiology; Non-albumin proteinuria; Obesity-related kidney disease; Tubular proteinuria; Arterial stiffness; Carotid-femoral pulse wave velocity
• ISSN: 1871-403X
• DOI: 10.1016/j.orcp.2023.10.002

Obesity is a well-established risk factor for kidney disease, and tubular damage can play a pivotal role in the development of obesity-related kidney damage. This study aimed to investigate the pathophysiological pathways involved in the development of non-albumin proteinuria (NAP), a marker of tubular involvement, in a cohort of subjects with severe obesity and preserved kidney function. A total of 106 subjects with BMI ≥ 35 kg/m2 in waiting list for bariatric surgery underwent blood chemistry analysis including metabolic and lipid profile, vascular tests for cardiovascular risk stratification and a comprehensive assessment of kidney function, including renal resistive index (RRI) and NAP measurement. Nineteen patients with ACR ≥ 30 mg/g regardless of NAP values (ALB+), nineteen with NAP≥ 150 mg/g and albuminuria < 30 mg/g (iNAP) and sixty-eight without proteinuria (No-P) were found. Both ALB+ and iNAP groups exhibited a higher prevalence of hypertension and anti-hypertensive treatment compared to No-P, while the prevalence of diabetes was similar between groups. Concerning lipid profile, no differences in total, HDL and LDL cholesterol were found, while ALB+ patients had higher serum triglyceride levels than the other two groups. RRI and carotid-femoral pulse wave velocity (cf-PWV) was significantly higher in ALB+ and iNAP groups compared to No-P. Remarkably, cf-PWV remained still significant after adjustment for age, sex and MBP (p = 0.0004). In overall population, a multiple regression analysis showed that cf-PWV was an independent determinant of NAP in a model including age, sex, glycated hemoglobin, systolic and mean blood pressure (R2 =0.17, p = 0.031). iNAP subjects showed increased arterial stiffness comparable to that observed in ALB+ group, suggesting that they may represent a subgroup at higher cardiovascular risk, often unrecognized in clinical practice.