# Serum Osteopontin and Procollagen Type 1 N-Terminal Propeptide Concentrations: Links to Liver Function, Muscle Mass, and Bone Mineral Density in MASLD and Hypertension

## TL;DR

This study explores how bone metabolism markers relate to liver health, muscle mass, and bone density in patients with fatty liver disease and high blood pressure.

## Contribution

The study identifies specific associations between serum OPN and P1NP levels with liver function, muscle mass, and bone health in patients with MASLD and hypertension.

## Key findings

- Lower serum OPN levels correlate with worse liver function and higher liver stiffness in MASLD and HTN patients.
- Serum P1NP levels are reduced in patients with decreased skeletal muscle mass.
- OPN levels are inversely associated with metabolic indicators like waist circumference and epicardial fat thickness.

## Abstract

Background/Objectives: Increasing evidence suggests that metabolic dysfunction-associated steatotic liver disease (MASLD) and hypertension (HTN), a well-established cardiometabolic risk factor, both negatively impact bone metabolism. This study aimed to investigate the associations between bone turnover markers (BTMs)—namely, osteopontin (OPN) and procollagen type 1 N-terminal propeptide (P1NP)—and metabolic health indicators, non-invasive measures of liver disease severity, as well as skeletal muscle mass (SMM), muscle strength, and bone mineral density (BMD) in patients with MASLD and HTN. Methods: We enrolled 117 patients diagnosed with MASLD and HTN and conducted anthropometric measurements, laboratory analyses, abdominal ultrasound, and point shear-wave elastography. Muscle strength was evaluated using grip strength measurements and the Five Times Sit-to-Stand Test (FTSST). SMM and BMD were quantified using dual-energy X-ray absorptiometry (DEXA). Serum OPN and P1NP concentrations were quantified using enzyme-linked immunosorbent assays (ELISAs). Results: Serum OPN concentrations below 2.89 ng/mL were associated with significantly elevated levels of AST (p = 0.001), ALT (p = 0.006), and GGT (p = 0.025), while serum P1NP concentrations above 47.5 pg/mL were associated only with significantly elevated GGT levels (p = 0.024). In addition, patients with MASLD and HTN with lower serum OPN levels had higher liver stiffness values (p = 0.003). Serum OPN concentrations were inversely associated with the following metabolic health indicators: waist circumference (WC, p < 0.001) and epicardial fat thickness (EFT, p = 0.001). In addition, they were significantly elevated in patients with MASLD and HTN who had decreased spinal BMD (p = 0.017). In turn, serum P1NP levels were reduced in patients with decreased SMM (p = 0.023). Conclusions: These findings in patients with MASLD and HTN suggest an association between serum P1NP levels and SMM, and between OPN levels and spinal BMD, indicating a potential interplay among liver function, muscle mass, and bone health. Furthermore, OPN appeared to be strongly associated with overall metabolic health indicators, such as WC and EFT, whereas P1NP exhibited a stronger association with muscle mass.