Chronic Hepatitis C May Contribute to an Elevated Risk of Bone Fractures in Postmenopausal Women

Chronic hepatitis C virus (HCV) infection has been linked to a variety of extra-hepatic (outside the liver) complications. Chronic liver disease is a recognized risk factor for metabolic bone disease, and a study presented at the Digestive Disease Week 2008 conference last month in San Diego suggests than HCV infection may contribute to bone fractures in postmenopausal women.

Kavinderjit Nanda and colleagues conducted a study to determine the effect of chronic HCV infection on the development of metabolic bone disease in a homogenous cohort of postmenopausal Irish women. The investigators enrolled 50 women who had all been exposed to genotype 1b HCV via contaminated immunoglobulin in 1977. The cohort included 26 women with chronic HCV infection (PCR positive) and 24 who had spontaneously cleared the virus (PCR negative). Both groups were demographically similar.

Clinical, biochemical, and histological data were obtained from medical records. Study participants completed a prospective questionnaire regarding onset of menstruation, number of pregnancies and deliveries, menopause status, and hormone use. Body mass index (BMI) was assessed, and bone mineral density (BMD) was measured in the lumbar spine and hip using DEXA scans. Markers of bone turnover (resorption and formation) were measured in fasting blood and urine samples.

Results

• Compared with the PCR negative group, the PCR positive women had higher liver aminotransferase (ALT and AST) levels, greater histological activity, and more extensive fibrosis (P = 0.001).

• Most of the PCR positive women had mild-to-moderate liver disease, but nearly 50% had fibrosis and 2% had cirrhosis.

• There were no statistically significant differences between the 2 groups with regard to number of years post-menopause, serum calcium, parathyroid hormone, vitamin D, bone turnover markers, or bone mineral density.

• However, the PCR positive chronically infected women had more fractures than the PCR negative women during the follow-up period (12 vs 1; P = 0.013).

• PCR positive women who experienced fractures had been menopausal for longer durations than those without fractures (12.5 vs 5.3 years; P = 0.01).

• PCR positive women with fractures had lower body mass index (24.3 vs 28.3 kg/m2; P = 0.48) and lower bone mineral density of the lumbar spine (0.802 vs 0.943 g/cm2; P = 0.04) and hip (0.815 vs 0.951 g/cm2; P = 0.004) than those without fractures.

• PCR positive women with and without bone fractures did not differ, however, with regard to liver disease severity or levels of bone turnover markers.

Conclusion

"In our cohort of postmenopausal women, HCV infection alone does not appear to increase the risk of metabolic bone disease," the researchers concluded. "However, PCR positive women who are postmenopausal longer are at increased risk of developing fractures, especially those with lower BMD and lower BMI."

Based on these findings, they recommended that, "Bone protection strategies should be implemented [in the] early post menopause [period] to prevent fractures in these patients."

6/03/08

Reference
KS Nanda, EJ Ryan, M McKenna, and others. Chronic hepatitis C virus (HCV) infection in a cohort of postmenopausal Irish women contributes to the development of bone fractures. Digestive Disease Week (DDW) 2008. San Diego, CA. May 17-22, 2008. Abstract W1021.