Renal osteodystrophy in the obesity era: Is metabolic syndrome relevant?

Abstract

BackgroundObservational studies have shown a beneficial effect of obesity on bone health; however, most of those studies were not based on bone biopsies. Metabolic syndrome (MetS) could have an effect on bone remodeling. However, there are no data on the effects of MetS in the presence of renal osteodystrophy.ObjectiveThe aim of this study was to investigate associations between MetS and renal osteodystrophy using the bone histomorphometric turnover-mineralization-volume (TMV) classification.Design, setting, participants & measurementsThis observational cross-sectional study included 55 hemodialysis patients (28 women/27 men) who were evaluated for MetS and bone histomorphometry. Biochemical parameters included calcium, phosphorus, alkaline phosphatase, intact parathyroid hormone (iPTH), 25-hydroxyvitamin D, free serum leptin, fibroblast growth factor 23 (FGF23), intact osteocalcin, sclerostin (Scl), glucose, insulin, and thyroid hormones. Robust models of multivariate linear regressions were used for the statistical analyses.ResultsFemales had higher iPTH levels (1,143 vs. 358, p = 0.02). Patients with normal bone volume (BV/TV) had a higher prevalence of MetS (73.6% vs. 41.7%, p = 0.02) and higher serum phosphorus, C-terminal FGF23 and insulin levels. The multivariate regression analysis showed that low-density lipoprotein cholesterol (LDL) was positively correlated with bone formation rate (BFR/BS) and negatively associated with mineralization lag time. Bone volume was negatively associated with age but positively associated with MetS. Body mass index (BMI) was not correlated with any of the bone histomorphometric parameters.ConclusionOur results suggest that MetS is not a risk factor for low bone volume in hemodialysis patients. Furthermore, BMI alone was not related to bone volume in this population.

Sciadonic acid attenuates high-fat diet-induced bone metabolism disorders in mice

“…High levels of Pi are prone to impaired metabolism of Ca and Pi, which affects Ca absorption and thus is detrimental to bone health. 34,35 In HFD mice, which usually have reduced Ca and elevated Pi levels, dietary intervention with SC significantly mitigated the increase in Pi levels and elevated bone Ca content and serum Ca levels. Some research studies have suggested that fatty acids can influence the secretion and activity of parathyroid hormone (PTH), a key regulator of calcium and phosphorus levels in the blood.…”

Caloric Intake in Renal Patients: Repercussions on Mineral Metabolism

“…In addition to promoting direct kidney damage, high caloric intake also affects renal disease indirectly (through the development of obesity and type 2 diabetes). Obesity may influence the progression of chronic kidney disease (CKD) due to its effects on renal hemodynamics that result in hyperfiltration, increased caloric intake and reduced caloric intake may promote bone disorders [24][25][26][27], although their influence on CKD-MBD has not been sufficiently explored [28].…”

“…In addition, changes in mineral metabolism are often accompanied by bone disease [ 23 ]. Emerging data indicate that both excessive caloric intake and reduced caloric intake may promote bone disorders [ 24 , 25 , 26 , 27 ], although their influence on CKD-MBD has not been sufficiently explored [ 28 ].…”

Energy-Dense Diets and Mineral Metabolism in the Context of Chronic Kidney Disease–Metabolic Bone Disease (CKD-MBD)

“…All of these CKD-associated derangements are collectively known as metabolic bone disease (MBD) [12]. Emerging evidence indicates that excessive caloric intake and obesity are also likely to promote bone disorders [13,14], although their influence on CKD-MDB is unclear [15].…”