Faculty Bibliography

Data from the 2003-2010 National Health and Nutrition Examination Survey (NHANES) indicate that about 3.6 million people in the United States have antibodies to the hepatitis C virus, of whom 2.7 million are currently infected. NHANES, however, excludes several high-risk populations from its sampling frame, including people who are incarcerated, homeless, or hospitalized; nursing home residents; active-duty military personnel; and people living on Indian reservations. We undertook a systematic review of peer-reviewed literature and sought out unpublished presentations and data to estimate the prevalence of hepatitis C in these excluded populations and in turn improve the estimate of the number of people with hepatitis C in the United States. The available data do not support a precise result, but we estimated that 1.0 million (range 0.4 million-1.8 million) persons excluded from the NHANES sampling frame have hepatitis C virus antibody, including 500,000 incarcerated people, 220,000 homeless people, 120,000 people living on Indian reservations, and 75,000 people in hospitals. Most are men. An estimated 0.8 million (range 0.3 million-1.5 million) are currently infected. Several additional sources of underestimation, including nonresponse bias and the underrepresentation of other groups at increased risk of hepatitis C that are not excluded from the NHANES sampling frame, were not addressed in this study. CONCLUSION: The number of US residents who have been infected with hepatitis C is unknown but is probably at least 4.6 million (range 3.4 million-6.0 million), and of these, at least 3.5 million (range 2.5 million-4.7 million) are currently infected; additional sources of potential underestimation suggest that the true prevalence could well be higher.

Abstract Although recent studies report a high prevalence of vitamin D deficiency in HIV-infected adults similar to that in the general population, metabolic complications of vitamin D deficiency may be worsened with HIV infection and remain insufficiently characterized. We conducted a retrospective cross-sectional cohort study to determine prevalence and correlates of vitamin D deficiency and hyperparathyroidism among HIV-infected patients attending an urban clinic. Vitamin D deficiency was defined as 25(OH)-vitamin D <20 ng/ml and insufficiency as 20 to <30 ng/ml, and hyperparathyroidism as parathyroid-hormone >65 pg/ml. We used the X(2) test to compare proportions and logistic regression to assess for associations. Among 463 HIV-infected patients, the prevalence of vitamin D deficiency was 59%. The prevalence of hyperparathyroidism was 30% among patients with vitamin D deficiency, 23% among those with insufficiency, and 12% among those with sufficient vitamin D levels. Vitamin D deficiency was associated with increased odds of hyperparathyroidism. Severe vitamin D deficiency was associated with elevated alkaline phosphatase, a marker for increased bone turnover. Although efavirenz use was associated with vitamin D deficiency, and protease inhibitor use with decreased odds of vitamin D deficiency, there was no statistical difference in rates of hyperparathyroidism stratified by combination antiretroviral therapy (cART) use. Given the increased risk of osteopenia with HIV infection and cART use, vitamin D supplementation for all HIV-infected patients on cART should be prescribed in accordance with the 2011 Endocrine Society guidelines. In HIV-infected patients with severe vitamin D deficiency or hyperparathyroidism, screening for osteomalacia and osteopenia may be warranted.

Abstract The American Diabetes Association now recommends hemoglobin A(1c) (HbA(1c)) screening for the diagnosis of diabetes. It has been reported that HbA(1c) levels underestimate glycemic levels in HIV-infected persons. We examined the performance of HbA(1c) as a screening test for diabetes in a group of HIV-infected people without diabetes. We conducted a retrospective cross-sectional cohort study among HIV-infected patients determining the sensitivity and specificity of HbA(1c) as a screening test compared to fasting blood glucose (FBG). The effect of treatment regimen on the relationship between HbA(1c) and FBG was assessed by multiple linear regressions. Twenty-two of the 395 patients included in the study were newly diagnosed with diabetes based on FBG>/=126 mg/dL. Using a cutoff of HbA(1c)>/=6.5%, HbA(1c) had a sensitivity of 40.9% and specificity of 97.5% for identification of incident diabetes. At an HbA(1c) level of 5.8% the product of sensitivity and specificity was maximized, with values of 88.8% and 77.5% respectively. Higher mean cell volume (MCV) values (p=0.02) and current use of a non-nucleoside reverse transcriptase inhibitors (NNRTIs; p=0.02) significantly increased the slope, while PI use significantly decreased the slope (p<0.001), of the linear regression of HbA(1c) compared to FBG. Tenofovir use did not significantly alter the slope or y-intercept of the line. Among HIV-infected nondiabetic patients, HbA(1c) is insensitive, although highly specific for diagnosing diabetes. Current antiretroviral (ART) use has significant and variable influence on the relationship between HbA(1c) and FBG. The use of HbA(1c) in conjunction with FBG may be the best modality to screen for diabetes.

PURPOSE OF REVIEW: This review addresses the associations between coronary heart disease and antiretroviral medications, with a specific focus on medications that appear to have neutral or positive effects on coronary heart disease risk factors. RECENT FINDINGS: Studies have linked combination antiretroviral therapy with an increased risk of coronary heart disease. Often implicated are the effects of these medications on the metabolic risk factors for coronary heart disease, specifically lipids and glucose homeostasis. Many newer antiretrovirals have fewer metabolic side effects, and antiretrovirals in general may be cardioprotective by reducing inflammation. Whether use of specific antiretroviral regimens will translate into improved cardiovascular outcomes remains to be seen. SUMMARY: Some antiretrovirals appear to be at least neutral with regards to coronary heart disease risk, but it is not clear if any are truly cardioprotective. Nonetheless, it is prudent to consider regimens with limited metabolic side effects in patients with pre-established coronary heart disease risk.