Progranulin concentration in relation to bone mineral density among obese individuals

Abstract

Objective: Adipose tissue, particularly visceral adipose tissue, secretes a variety of cytokines, among which progranulin is a glycoprotein related to the immune system. Along with other secreted proteins, progranulin may be associated with bone mineral density. The aim of this study was to find out whether there are associations between the progranulin and bone mineral density among obese people. Subjects and methods: This cross-sectional study was conducted on 244 obese participants (aged 22-52). Serum progranulin, high sensitive C-reactive protein, oxidised-low dencity lipoprotein, tumor necrosis factor-α, parathormone, vitamin D, and interleukins of 1 β, 4, 6, 10, 13, and 17 concentrations were measured. Anthropometric measurements, body composition and bone mineral density were also assessed. Results: Serum progranulin was directly associated with interleukin-6 and interleukin-1β, while it had a negative association with interleukin-17 and tumor necrosis factor-α. We also observed a statistically significant direct association between progranulin concentration and visceral fat, abdominal fat, waist, abdominal and hip circumferences, hip T-score, and Z-score and T-score for the lumbar region. A partial correlation test has also shown a significant positive correlation regarding serum progranulin and the hip Z-score. Moreover, progranulin level is inversely associated with ospteopenia (P = 0.04 and CI: 0.17,0.96 ). Conclusion: Our study revealed that central obesity may be related to increased progranulin concentration. In addition, progranulin concentration was directly related to bone formation parameters, which indicates the protective effects of progranulin on bone density. Further studies are needed to clarify the exact mechanisms underlying these associations. Arch Endocrinol Metab. 2018;62(2):179-86

Progranulin is essential for bone homeostasis and immunology

“…An increasing number of studies have investigated the role of PGRN in osteogenesis under inflammatory conditions. Serum PGRN concentrations are positively correlated with serum IL‐1β and IL‐6 levels and inversely correlated with IL‐17 and TNF‐α levels 59 …”

“…58 Moreover, clinical cross-sectional studies in participants with obesity have been conducted, revealing that PGRN concentrations are closely positively correlated with bone formation. 59 Collectively, PGRN is a novel regulator that triggers the transition from cell proliferation to osteoblast differentiation.…”

“…Serum PGRN concentrations are positively correlated with serum IL-1β and IL-6 levels and inversely correlated with IL-17 and TNF-α levels. 59 Prolonged bone fracture healing has been reported in immune inflammatory environments, for example, T2DM and CP. CP is a highly prevalent (∼11.2% globally), dynamic inflammatory infectious disease that destroys soft and hard tissue.…”