Study Shows Rising Global Prevalence of PAD

August 1, 2013—In The Lancet, Professor F. Gerald R. Fowkes, MBChB, PhD, et al published a systematic review and analysis comparing global estimates of prevalence and risk factors for peripheral artery disease (PAD) in 2000 and 2010. The study is available online ahead of print in The Lancet.

The investigators found that PAD has become a global problem in the 21st century in low- and middle-income countries (LMIC), as well as in high-income countries (HIC). Globally, 202 million people were living with PAD in 2010, 69.7% of them in LMIC, including 54.8 million in southeast Asia and 45.9 million in the western Pacific region. During the preceding decade, the number of individuals with PAD increased by 28.7% in LMIC and 13.1% in HIC.

Governments, nongovernmental organizations, and the private sector in LMIC need to address the social and economic consequences and assess the best strategies for optimum treatment and prevention of this disease, concluded the investigators in The Lancet.

According to the investigators, this study provides the first comparison of the prevalence of PAD between HIC and LMIC, establishes the primary risk factors for PAD in these settings, and estimates the number of people living with PAD regionally and globally. Lower extremity PAD is the third leading cause of atherosclerotic cardiovascular morbidity after coronary artery disease and stroke, noted the investigators.

As summarized in The Lancet, the investigators conducted a systematic review of the literature on the prevalence of PAD, in which they searched for community-based studies since 1997 that defined PAD as an ankle-brachial index ≤ 0.9. Epidemiological modeling was used to define age-specific and sex-specific prevalence rates in HIC and LMIC and combined them with United Nations population numbers for 2000 and 2010 to estimate the global prevalence of PAD.

Within a subset of studies, the investigators performed meta-analyses of odds ratios associated with 15 putative risk factors for PAD to estimate their effect size in HIC and LMIC. They then used the risk factors to predict PAD numbers in eight World Health Organization regions (three HIC and five LMIC).

In the study’s findings, the investigators noted that 34 studies satisfied the inclusion criteria, 22 from HIC and 12 from LMIC. These studies included 112,027 participants, of which, 9,347 had PAD. Sex-specific prevalence rates increased with age and were broadly similar in HIC and LMIC and in men and women. The prevalence in HIC at 45 to 49 years of age was 5.28% (95% confidence interval, 3.38%–8.17%) in women and 5.41% (3.41%–8.49%) in men. In HIC, at age 85 to 89 years, the PAD prevalence was 18.38% (11.16%–28.76%) in women and 18.83% (12.03%–28.25%) in men.

Prevalence in men was lower in LMIC than in HIC (2.89% [2.04%–4.07%] at 45–49 years of age and 14.94% [9.58%–22.56%] at 85–89 years of age). In LMIC, rates were higher in women than in men, especially at younger ages (6.31% [4.86%–8.15%] in women 45–49 years of age).

Smoking was an important risk factor in both HIC and LMIC, with a meta-odds ratio for current smoking of 2.72 (95% confidence interval, 2.39–3.09) in HIC and 1.42 (1.25–1.62) in LMIC, followed by diabetes (1.88 [1.66–2.14] vs 1.47 [1.29–1.68]), hypertension (1.55 [1.42–1.71] vs 1.36 [1.24–1.5]), and hypercholesterolemia (1.19 [1.07–1.33] vs 1.14 [1.03–1. 25]), reported the investigators in The Lancet.