Body mass index and body fat distribution as renal risk factors: a focus on the role of renal haemodynamics

Abstract

Weight excess and/or central body fat distribution are associated with increased long-term renal risk, not only in subjects with renal disease or renal transplant recipients, but also in the general population. As the prevalence of weight excess is rising worldwide, this may become a main renal risk factor on a population basis, even more so because the risk extends to the overweight range. Understanding the mechanisms of this detrimental effect of weight excess on the kidneys is needed in order to design preventive treatment strategies. The increased risk associated with weight excess is partly attributed to associated comorbid conditions, such as hypertension, dyslipidaemia, insulin resistance and diabetes; however, current evidence supports a direct pathogenetic role for renal haemodynamics as well. Weight excess is associated with an altered renal haemodynamic profile, i.e. an increased glomerular filtration rate relative to effective renal plasma flow, resulting in an increased filtration fraction (FF). This renal haemodynamic profile is considered to reflect glomerular hyperfiltration and glomerular hypertension, resulting from a dysbalance between afferent and efferent arterial vasomotor balance. This unfavorable renal haemodynamic profile was found to be associated with renal outcome in experimental models and in human renal transplant recipients, and is associated with a blunted sodium excretion, and reversible by weight loss, renin-angiotensin-aldosterone system blockade or by dietary sodium restriction. More recent evidence showed that a central body fat distribution is also associated with an increased FF, even independent of overall weight excess. In this review, we provide an overview on current literature on the impact of weight excess and central body fat distribution on the renal haemodynamic profile in humans, and its possible role in progressive renal damage.

Central obesity associates with renal hyperfiltration in the non-diabetic general population: a cross-sectional study

“…A large longitudinal study by Park et al of 43,503 Korean health screening participants found that a RHF definition based on eGFR was associated with all-cause mortality, even when adjusted for age, sex, muscle mass, diabetes and hypertension [16]. Although several studies have been conducted on the relationship between obesity and RHF [17–25], it remains unclear whether these two conditions are also associated in the general non-diabetic population. The most important reason has been that there is currently no consensus on the definition of the term “hyperfiltration”.…”

The impact of hyperfiltration on the diabetic kidney

“…Augmented tubulo-glomerular feedback, proximal tubular Na resorption, increased plasma volume secondary to salt retention and systemic hypertension are hallmark features in obese patients, similar to that observed in diabetes [82]. Furthermore, recent evidence showed that a central body fat distribution is also associated with an increased filtration fraction, even independent of overall weight excess [83]. Insulin resistance causes an imbalance between afferent and efferent arterial vasomotor activity, increasing transcapillary pressure gradient causing glomerular HF.…”

Diagnóstico de infección por VIH por el hallazgo incidental de alteraciones ultraestructurales en una biopsia renal: Report of one case

“…Por ello se realizó una BpR. Ella confirmó la sospecha clínica de EMBD (Figura 1) y mostró glomérulos hipertróficos compatibles con hiperfiltración glomerular, situación frecuente de observar en sujetos con resistencia a la insulina o gran masa corporal (desproporción entre masa corporal/masa renal) 13,14 . También, la ultraestructura mostró fusión pedicelar muy extensa, lo que explica la magnitud de la proteinuria.…”