Volume 13 Supplement 4
High plasma levels of parathyroid hormone (PTH) are associated with an increased cardiovascular risk among HIV-infected subjects
© Castagna et al; licensee BioMed Central Ltd. 2010
Published: 8 November 2010
Elevated PTH plasma levels are associated to an increased cardiovascular risk (CVR) possibly due to a PTH effect on vascular calcification, myocardial impairment and hypertension.
Purpose of the study
To assess the association between CVR and PTH levels in HIV-infected patients (pts).
HIV-infected subjects followed at the Infectious Disease Department of IRCCS San Raffaele, with at least one PTH plasma value and a contemporary CVR determination. CVR was calculated according to Framingham 10-years equation (Anderson et al.) Cochran-Armitage test for trend and Spearman correlation were calculated at univariate analysis. Logistic regression was applied at multivariable analysis.
Up to date 280 pts met the inclusion criteria; median (IQR) age was 48.4 (44.4-55.9) years, 205 (73.2%) male, 14.9 (9.3-20.4) years after HIV-infection, 104 (37.1%) smokers, 22 (7.9%) with a previous diagnosis of diabetes, PTH plasma level was 62.7 (49.5-81.5)pg/ml [82 (33%) pts > upper normal limit], vitamin D (25-OH D3) level was 22.5(14.8-31.0) ng/ml, systolic pressure was 120(110-135) mmHg, total cholesterol 192 (169-220) mg/dL, creatinine 0.83 (0.71-0.98) mg/dL, current CD4 cell count was 549 (391-740) cells/mm3 and HIV-RNA< 50cp/ml in 235(83.9%) subjects. Overall CVR was 8 (4.3-13.8)% at 10 years. Eighty-four(30.0%) pts presented a CVR below 5%, 93(33.2%) between 5 and 10%, 46(16.4%) between 10 and 15%, 28(10.0%) between 15 and 20% and 29(10.6%) above 20% risk. PTH levels differed among classes of CVR [CVR <5%, 5-10%, 10-15%, 15-20, >20% had median PTH levels of 57.3, 63.6, 67.0, 73.3 and 65.3 pg/ml, respectively, (p=0.032)]. CVR was positively correlated with PTH (r=0.148, p=0.0134), creatinine (r=0.316, p<0.0001), triglycerides (r=0.300, p<0.0001) but not with vitamin D level (r= -0.102; p=0.123). After adjusting for PTH plasma levels, years of antiretroviral therapy (ART), years of HIV-infection, nadir and current CD4 cell count, detectable HIV-RNA, HIV transmission risk factor, triglycerides and creatinine levels, a CVR>10% was predicted by increasing PTH levels (OR=1.353 per 20-pg/mL increase, 95%CI: 1.074-1.802, p=0.028)as well as by increasing creatinine levels (OR=1.442 per 0.1-mg/dL increase, 95%CI:1.201-1.774, p=0.0002).
Among HIV-infected patients elevated PTH levels were related to increased CVR and independently predicted a 10-years CVR above 10%. The interplay between bone metabolism and CVR needs to be further investigated.
This article is published under license to BioMed Central Ltd. This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.