Comparison of brachial and carotid artery ultrasound for assessing extent of subclinical atherosclerosis in HIV: a prospective cohort study

Abstract

BackgroundNon-invasive surrogate measures which are valid and responsive to change are needed to study cardiovascular risks in HIV. We compared the construct validity of two noninvasive arterial measures: carotid intima medial thickness (IMT), which measures anatomic disease; and brachial flow-mediated vasodilation (FMD), a measure of endothelial dysfunction.MethodsA sample of 257 subjects aged 35 years or older, attending clinics in five Canadian centres, were prospectively recruited into a study of cardiovascular risk among HIV subjects. The relationship between baseline IMT or FMD and traditional vascular risk factors was studied using regression analysis. We analyzed the relationship between progression of IMT or FMD and risk factors using fixed-effects models. We adjusted for use of statin medication and CD4 count in both models.ResultsBaseline IMT was significantly associated with age (p < 0.001), male gender (p = 0.034), current smoking status (p < 0.001), systolic blood pressure (p < 0.001) and total:HDL cholesterol ratio (p = 0.004), but not statin use (p = 0.904) and CD4 count (p = 0.929). IMT progression was significantly associated with age (p < 0.001), male gender (p = 0.0051) and current smoking status (p = 0.011), but not statin use (p = 0.289) and CD4 count (p = 0.927). FMD progression was significantly associated with current statin use (p = 0.019), but not CD4 count (p = 0.84). Neither extent nor progression of FMD was significantly associated with any of the examined vascular risk factors.ConclusionIMT correlates better than FMD with established cardiovascular risk factors in this cohort of HIV patients. Standardization of protocols for FMD and IMT will facilitate the comparison of results across studies.

A Prospective Cohort Study of Periodontal Disease Measures and Cardiovascular Disease Markers in HIV-Infected Adults

“…Our results showing a slight improvement in FMD over time in HIV-infected adults on HAART (Table 2) are in agreement with findings of improved FMD at 4 and 24 weeks after HAART initiation as reported by Torriani et al, 8 but differ from findings of worsened FMD over 1 year in a more heterogeneous cohort of HIV-infected adults as reported by Obueyungbo et al 17 We propose that our results are more similar to those of Torriani et al because, like their cohort, ours had recently started HAART, had a relatively low baseline CD4 + T cell count, and most but not all of our subjects (59%) achieved plasma HIV RNA levels < 50 copies/ml at the final study visit. In the context of other longitudinal studies, our PD, periodontal disease; IMT, carotid artery intima media thickness; PPD, periodontal probing depth; REC, gingival recession; CAL, clinical attachment level; BOP, bleeding on probing; P. gingivalis, Porphyromonas gingivalis; T. denticola, Treponema denticola; T. forsythia, Tannerella forsythia; 23S rRNA, 23S ribosomal RNA.…”

“…Our finding that IMT worsened by 0.0035 mm per year (i.e., 0.007 mm/2 years) agree with four previous longitudinal studies of HIV-infected cohorts, [14][15][16][17] but are closest to findings by Currier et al indicating that IMT progressed a median of 0.0096 mm/year in a PI-treated group and 0.0058 mm/year in a non-PI-treated group. 15 Among several pooled HIVnegative cohorts, the annual mean change in common carotid IMT is 0.015 mm 55 ; thus, the institution of HAART and possibly other unmeasured effects (i.e., improved care, health education) might have played a role in putting our subjects at a risk profile similar to the general population.…”

“…We selected these variables based on prior published studies. 4,5,10,[13][14][15][16][17]40,41 Results Among the 58 enrolled subjects, 11 did not have follow-up visits, two did not definitively initiate HAART, and two had full-mouth extractions during the study, resulting in an analytic sample of 43 subjects. For these 43 subjects, the median time on study was 24 months (range: 6-44), with 81% completing one ultrasound follow-up visit and 19% completing two or more ultrasound follow-up visits, resulting in a total of 94 visits.…”

“…[1][2][3] Numerous clinical studies have examined the impact of HIV infection on cardiovascular disease (CVD) risk as assessed by carotid artery intima media thickness (IMT) and/or brachial artery flow-mediated dilation (FMD). [4][5][6][7][8][9][10][11][12][13][14][15][16][17] CVD progression is reportedly accelerated in HIV-infected subjects, 14 though this finding has not been consistent across studies. 15 While highly active antiretroviral therapy (HAART) may itself exacerbate CVD risk, 7 the relative contributions of HIV infection [18][19][20] and its resulting long-term immune, 6 inflammatory, and coagulation effects [21][22][23] have not been completely elucidated.…”

“…Longitudinal findings in an HIV-infected cohort reported by Obueyungbo et al, wherein traditional risk factors for CVD (i.e., age, male gender, and smoking status) were significantly related to IMT but not FMD, would tend to support the latter interpretation. 17 Our study had several strengths. We followed a relatively homogeneous cohort in terms of stage of HIV disease-as most of our cohort had recently started HAART.…”