Bone Mineral Density, Bone Turnover, and Systemic Inflammation in Non-cirrhotics with Chronic Hepatitis C

Background: Whether chronic HCV, a disease characterized by systemic inflammation, impacts bone mineral density (BMD) independent of cirrhosis is unknown. Aim: We aimed to evaluate the association between BMD, systemic inflammation, and markers of bone turnover in chronic HCV without cirrhosis. Methods: Non-cirrhotics, 40–60 years old, with chronic HCV underwent measurement of: (1) BMD by dual-energy X-ray absorptiometry scan and (2) serum markers of systemic inflammation and bone turnover. By Chi-squared or t test, we compared those with normal versus low BMD. Results: Of the 60 non-cirrhotics, 53 % were female and 53 % Caucasian. Mean (SD) age was 53.3 years (5.7), total bilirubin 0.7 mg/dL (0.3), creatinine 0.8 mg/dL (0.2), and body mass index 28.4 kg/m2 (6.5). Low BMD was observed in 42 %: 30 % had osteopenia, 12 % had osteoporosis. Elevated tumor necrosis factor α, interleukin-6, and C-reactive protein levels were found in 26, 32, and 5 %, respectively, but did not differ by BMD group (p > 0.05). Patients with low BMD had higher serum phosphorus (4.1 vs. 3.5 mg/dL) and pro-peptide of type 1 collagen (P1NP; 73.1 vs. 47.5 ng/mL) [p < 0.05], but similar bone-specific alkaline phosphatase, serum C-telopeptide, and parathyroid hormone levels. Conclusions: Low BMD is prevalent in 40- to 60-year-old non-cirrhotics with chronic HCV, but not associated with systemic inflammatory markers. Elevated P1NP levels may help to identify those at increased risk of bone complications in this population. Chronic HCV should be considered a risk factor for bone loss, prompting earlier BMD assessments in both men and women

Changes in vertebral bone marrow fat and bone mass after gastric bypass surgery: A pilot study.

Bone marrow fat may serve a metabolic role distinct from other fat depots, and it may be altered by metabolic conditions including diabetes. Caloric restriction paradoxically increases marrow fat in mice, and women with anorexia nervosa have high marrow fat. The longitudinal effect of weight loss on marrow fat in humans is unknown. We hypothesized that marrow fat increases after Roux-en-Y gastric bypass (RYGB) surgery, as total body fat decreases. In a pilot study of 11 morbidly obese women (6 diabetic, 5 nondiabetic), we measured vertebral marrow fat content (percentage fat fraction) before and 6 months after RYGB using magnetic resonance spectroscopy. Total body fat mass declined in all participants (mean ± SD decline 19.1 ± 6.1 kg or 36.5% ± 10.9%, p<0.001). Areal bone mineral density (BMD) decreased by 5.2% ± 3.5% and 4.1% ± 2.6% at the femoral neck and total hip, respectively, and volumetric BMD decreased at the spine by 7.4% ± 2.8% (p<0.001 for all). Effects of RYGB on marrow fat differed by diabetes status (adjusted p=0.04). There was little mean change in marrow fat in nondiabetic women (mean +0.9%, 95% CI -10.0 to +11.7%, p=0.84). In contrast, marrow fat decreased in diabetic women (-7.5%, 95% CI -15.2 to +0.1%, p=0.05). Changes in total body fat mass and marrow fat were inversely correlated among nondiabetic (r=-0.96, p=0.01) but not diabetic (r=0.52, p=0.29) participants. In conclusion, among those without diabetes, marrow fat is maintained on average after RYGB, despite dramatic declines in overall fat mass. Among those with diabetes, RYGB may reduce marrow fat. Thus, future studies of marrow fat should take diabetes status into account. Marrow fat may have unique metabolic behavior compared with other fat depots