Low Insulin-Like Growth Factor-1 Level in Obesity Nephropathy: A New Risk Factor?

Abstract

IntroductionIGF-1 (insulin-like growth factor-1) is a hormone involved in cell growth and other important processes. In the kidney, IGF-1 has a stimulating effect, increasing the blood flow and glomerular filtration rate. Although many experimental animal studies regarding the role of IGF-1 in the kidney have been conducted, few human studies are available in the literature. Obesity is a cause of renal failure, and several glomerular lesions associated with obesity have been described. However, no studies regarding the levels of IGF-1 in morbidly obese patients with renal injury associated with obesity have been conducted.AimTo determine the serum IGF-1 concentrations in morbidly obese patients with normal renal function but with different types of early obesity-related glomerular lesions and to evaluate the possible relationship between IGF-1 and the presence of renal lesions.MethodsEighty morbidly obese patients with renal biopsy, including 11 patients with no evidence of renal lesion, 17 patients with single glomerulomegaly, 21 patients with single podocyte hypertrophy, 10 patients with glomerulomegaly and podocyte hypertrophy, 5 patients with focal segmental hyalinosis, and 16 patients with increased mesangial matrix and/or mesangial proliferation, participated in this study. Biological parameters, including serum IGF-1 concentrations with the standard deviation score for age (SDS-IGF-1), were determined for all patients.ResultsEighty patients (50 women and 30 men) with a mean BMI of 52.63 ± 8.71 and a mean age of 42.40 ± 9.45 years were included in this study. IGF-1, IGF-1 SDS and IGF-1BP3 levels according to the renal injury were compared (normal glomeruli: IGF-1 = 190.17 ± 72.46; glomerulomegaly: IGF-1 = 122.3 ± 50.05; podocyte hypertrophy: IGF-1 = 119.81 ± 60.34; focal segmental hyalinosis: IGF-1 170.98 ± 100.83, increased mesangial matrix and/or mesangial proliferation: IGF-1 117.73 ± 63.87). Statistically significant differences were observed between serum levels of IGF-1 and between the levels of SDS-IGF-1 by comparing the group without glomerular lesion with the group formed by patients with any type of glomerular injury. Logistic regression analysis was performed, with the dependent variable defined as the glomerular injury. In the multivariate analysis, only SDS-IGF-1 was associated with glomerular injury, and low levels of IGF-1 SDS were a risk factor for kidney injury.ConclusionsOur study demonstrates that low IGF-1 serum levels are associated with renal lesions in morbidly obese patients without overt clinical renal manifestations.

Obesity-induced cognitive impairment in older adults: a microvascular perspective

“…In addition to Nrf2, previous studies also provide evidence that insulin-like growth factor-1 (IGF-1)-mediated pathways exert multifaceted cerebromicrovascular protective effects, which act to preserve endothelial vasodilation and NVC (47, 76, 99-104). Aging results in decreased levels of circulating IGF-1 (102,(105)(106)(107). Mouse models of genetic IGF-1 deficiency were shown to exhibit accelerated neurovascular aging phenotype, characterized by neurovascular uncoupling, impaired endothelial NO production, and cognitive impairment (76).…”

Consequences of morbid obesity on the kidney. Where are we going?

“…Despite various attempts to elucidate the pathogenic mechanisms of renal disease in obesity, most of which have been experimental, there is still a lack of knowledge on this subject, and further investigation is needed. Only a few studies have reported associations among obesity, renal injury and inflammatory hormones [51–53]. Insulin-like growth hormone-1 (IGF-1) levels are decreased in obesity [54, 55].…”

“…Insulin-like growth hormone-1 (IGF-1) levels are decreased in obesity [54, 55]. We have recently identified a link between a low IGF-1 hormone level and the presence of renal injury in MO patients with early stages of ORG [53]. Additionally, IGF-1 gene expression has been shown to be decreased in kidney biopsies from MO patients with early stages of ORG compared with those from a normal-weight control group (M. Navarro, unpublished data), whereas expression of the proinflammatory genes IL-6 and glucose transporter-1 was increased (M. Navarro, unpublished data).…”

Growth hormone, growth hormone receptor and insulin-like growth factor serum levels in patients with obesity and food addiction

“…Consistently, our current study shows that IGF-1 levels are significantly lower in obesity group compared to healthy controls. In a study conducted with morbidly obese individuals, it has been reported that decreased serum IGF-1 levels are related with renal lesions [20].…”