High prevalence of peripheral atherosclerosis in a rapidly developing country

Global and regional prevalence, burden, and risk factors for carotid atherosclerosis: a systematic review, meta-analysis, and modelling study

BACKGROUND

Estimation of the epidemiological burden of carotid atherosclerosis can serve as a basis for prevention and management of cardiovascular disease. We aimed to provide the first estimation on the prevalence, number of cases, and risk factors for carotid atherosclerosis in the general population globally and regionally.

METHODS

In this systematic review, meta-analysis, and modelling study, we searched PubMed, MEDLINE, Embase, Global Health, and China National Knowledge Infrastructure for articles published from database inception until May 7, 2019, with no language restrictions, for population-based studies that quantified prevalence of carotid atherosclerosis by means of increased carotid intima-media thickness, carotid plaque, and carotid stenosis. Studies were eligible if they included bilaterally scanned carotid arteries using ultrasonography and defined increased carotid intima-media thickness as a thickness of 1·0 mm or more, carotid plaque as a focal carotid intima-media thickness of 1·5 mm or more encroaching into the lumen or at least 0·5 mm or 50% compared with the surrounding carotid intima-media thickness values, and carotid stenosis as 50% or more stenosis. Studies were excluded if the sample was not representative of the general population. We also included studies identified in our previous systematic review and meta-analysis of the prevalence of carotid atherosclerosis in China. We estimated age-specific and sex-specific prevalences of increased carotid intima-media thickness, carotid plaque, and carotid stenosis. We used UN population data to generate the number of people affected in 2000, 2015, and 2020. We did random-effects meta-analyses to assess the effects of risk factors for increased carotid intima-media thickness and carotid plaque. We derived regional numbers of people living with increased carotid intima-media thickness and carotid plaque in 2015 using a risk factors-based model by WHO region. All analyses were done in populations aged 30-79 years due to availability of data. This systematic review and meta-analysis is registered online on PROSPERO, CRD42019134709.

FINDINGS

We identified 8632 articles through our database search, of which 515 were eligible for full-text review, including 37 articles from our previous study, and 59 articles were eligible for inclusion in our systematic review and meta-analysis. Overall, in people aged 30-79 years in 2020, the global prevalence of increased carotid intima-media thickness is estimated to be 27·6% (95% CI 16·9-41·3), equivalent to 1066·70 million affected people and a percentage change of 57·46% from 2000; of carotid plaque is estimated to be 21·1% (13·2-31·5), equivalent to 815·76 million affected people and a percentage change of 58·97% from 2000; and carotid stenosis is estimated to be 1·5% (1·1-2·1), equivalent to 57·79 million affected people and a percentage change of 59·13% from 2000. The prevalence of increased carotid intima-media thickness, carotid plaque, and carotid stenosis increased consistently with age and was higher in men than in women. Current smoking, diabetes, and hypertension were common risk factors for increased carotid intima-media thickness and carotid plaque. In 2015, the Western Pacific region had the largest share of global cases of increased carotid intima-media thickness (317·62 million [33·36%] of 952·13 million affected people) and carotid plaque (240·77 million [33·20%] of 725·25 million), whereas the African region had the smallest share of cases of increased carotid intima-media thickness (59·08 million [6·21%]) and the Eastern Mediterranean region had the smallest share of carotid plaque cases (44·59 million [6·15%]).

INTERPRETATION

A substantial global burden of carotid atherosclerosis exists. Effective strategies are needed for primary prevention and management of carotid atherosclerosis. High-quality epidemiological investigations on carotid atherosclerosis are needed to better address the global burden of carotid atherosclerosis at finer levels.

FUNDING

None.

Sudden unexpected death from natural diseases: Fifteen years' experience with 484 cases in Seychelles

The aim of this study is to identify and subclassify sudden natural death (sudden death from natural diseases) cases in Seychelles. A total of 484 sudden natural death cases with autopsy at the Clinical Pathology Laboratory, Victoria Hospital, Seychelles between 1997 through 2012 were retrospectively reviewed. Among them, 363 cases (75%) were male and 121 (25%) were female. The most frequent sudden deaths were attributed to cardiovascular diseases (78.5%), and then followed by infectious diseases (9.9%), and gastrointestinal diseases (9.1%). This is the largest population-based study on sudden natural deaths in Seychelles.

Syndecan 4 is required for endothelial alignment in flow and atheroprotective signaling

Atherosclerotic plaque localization correlates with regions of disturbed flow in which endothelial cells (ECs) align poorly, whereas sustained laminar flow correlates with cell alignment in the direction of flow and resistance to atherosclerosis. We now report that in hypercholesterolemic mice, deletion of syndecan 4 (S4(-/-)) drastically increased atherosclerotic plaque burden with the appearance of plaque in normally resistant locations. Strikingly, ECs from the thoracic aortas of S4(-/-) mice were poorly aligned in the direction of the flow. Depletion of S4 in human umbilical vein endothelial cells (HUVECs) using shRNA also inhibited flow-induced alignment in vitro, which was rescued by re-expression of S4. This effect was highly specific, as flow activation of VEGF receptor 2 and NF-κB was normal. S4-depleted ECs aligned in cyclic stretch and even elongated under flow, although nondirectionally. EC alignment was previously found to have a causal role in modulating activation of inflammatory versus antiinflammatory pathways by flow. Consistent with these results, S4-depleted HUVECs in long-term laminar flow showed increased activation of proinflammatory NF-κB and decreased induction of antiinflammatory kruppel-like factor (KLF) 2 and KLF4. Thus, S4 plays a critical role in sensing flow direction to promote cell alignment and inhibit atherosclerosis.

An electronic medical record-linked biorepository to identify novel biomarkers for atherosclerotic cardiovascular disease

Background: Atherosclerotic vascular disease (AVD), a leading cause of morbidity and mortality, is increasing in prevalence in the developing world. We describe an approach to establish a biorepository linked to medical records with the eventual goal of facilitating discovery of biomarkers for AVD. Methods: The Vascular Disease Biorepository at Mayo Clinic was established to archive DNA, plasma, and serum from patients with suspected AVD. AVD phenotypes, relevant risk factors and comorbid conditions were ascertained by electronic medical record (EMR)-based electronic algorithms that included diagnosis and procedure codes, laboratory data and text searches to ascertain medication use. Results: Up to December 2012, 8800 patients referred for vascular ultrasound examination and non-invasive lower extremity arterial evaluation were approached, of whom 5268 consented. The mean age of the initial 2182 patients recruited was 70.4 ± 11.2 years, 62.6% were men and 97.6% were whites. The prevalences of AVD phenotypes were: carotid artery stenosis 48%, abdominal aortic aneurysm 21% and peripheral arterial disease 38%. Positive predictive values for electronic phenotyping algorithms were>0.90 for cases (and>0.95 for controls) for each AVD phenotype, using manual review of the EMR as the gold standard. The prevalences of risk factors and comorbidities were as follows: hypertension 78%, diabetes 29%, dyslipidemia 73%, smoking 70%, coronary heart disease 37%, heart failure 12%, cerebrovascular disease 20% and chronic kidney disease 19%. Conclusions: Our study demonstrates the feasibility of establishing a biorepository of plasma, serum and DNA, with relatively rapid annotation of clinical variables using EMR-based algorithms.

Association between conventional risk factors and different ultrasound-based markers of atherosclerosis at carotid and femoral levels in a middle-aged population

Ultrasound detection of sub-clinical atherosclerosis (ATS) may help identify individuals at high cardiovascular risk. Most studies evaluated intima-media thickness (IMT) at carotid level. We compared the relationships between main cardiovascular risk factors (CVRF) and five indicators of ATS (IMT, mean and maximal plaque thickness, mean and maximal plaque area) at both carotid and femoral levels. Ultrasound was performed on 496 participants aged 45-64 years randomly selected from the general population of the Republic of Seychelles. 73.4 % participants had ≥ 1 plaque (IMT thickening ≥ 1.2 mm) at carotid level and 67.5 % at femoral level. Variance (adjusted R2) contributed by age, sex and CVRF (smoking, LDL-cholesterol, HDL-cholesterol, blood pressure, diabetes) in predicting any of the ATS markers was larger at femoral than carotid level. At both carotid and femoral levels, the association between CVRF and ATS was stronger based on plaque-based markers than IMT. Our findings show that the associations between CVRF and ATS markers were stronger at femoral than carotid level, and with plaque-based markers rather than IMT. Pending comparison of these markers using harder cardiovascular endpoints, our findings suggest that markers based on plaque morphology assessed at femoral artery level might be useful cardiovascular risk predictors.

Divergent fifteen-year trends in traditional and cardiometabolic risk factors of cardiovascular diseases in the Seychelles

Objective

Few studies have assessed secular changes in the levels of cardiovascular risk factors (CV-RF) in populations of low or middle income countries. The systematic collection of a broad set of both traditional and metabolic CV-RF in 1989 and 2004 in the population of the Seychelles islands provides a unique opportunity to examine trends at a fairly early stage of the "diabesity" era in a country in the African region.

Methods

Two examination surveys were conducted in independent random samples of the population aged 25–64 years in 1989 and 2004, attended by respectively 1081 and 1255 participants (participation rates >80%). All results are age-standardized to the WHO standard population.

Results

In 2004 vs. 1989, the levels of the main traditional CV-RF have either decreased, e.g. smoking (17% vs. 30%, p < 0.001), mean blood pressure (127.8/84.8 vs. 130.0/83.4 mmHg, p < 0.05), or only moderately increased, e.g. median LDL-cholesterol (3.58 vs. 3.36 mmol/l, p < 0. 01). In contrast, marked detrimental trends were found for obesity (37% vs. 21%, p < 0.001) and several cardiometabolic CVD-RF, e.g. mean HDL-cholesterol (1.36 vs. 1.40 mmol/l, p < 0.05), median triglycerides (0.80 vs. 0.78 mmol/l, p < 0.01), mean blood glucose (5.89 vs. 5.22 mmol/l, p < 0.001), median insulin (11.6 vs. 8.3 μmol/l, p < 0.001), median HOMA-IR (2.9 vs. 1.8, p < 0.001) and diabetes (9.4% vs. 6.2%, p < 0.001). At age 40–64, the prevalence of elevated total cardiovascular risk tended to decrease (e.g. WHO-ISH risk score ≥10; 11% vs. 13%, ns), whereas the prevalence of the metabolic syndrome (which integrates several cardiometabolic CVD-RF) nearly doubled (36% vs. 20%, p < 0.001). Data on physical activity and on intake of alcohol, fruit and vegetables are also provided. Awareness and treatment rates improved substantially for hypertension and diabetes, but control rates improved for the former only. Median levels of the cardiometabolic CVD-RF increased between 1989 and 2004 within all BMI strata, suggesting that the worsening levels of cardiometabolic CVD-RF in the population were not only related to increasing BMI levels in the interval.

Conclusion

The levels of several traditional CVD-RF improved over time, while marked detrimental trends were observed for obesity, diabetes and several cardiometabolic factors. Thus, in this population, the rapid health transition was characterized by substantial changes in the patterns of CVD-RF. More generally, this analysis suggests the importance of surveillance systems to identify risk factor trends and the need for preventive strategies to promote healthy lifestyles and nutrition.

No further decrease in blood pressure when the interval between readings exceeds one hour

OBJECTIVE

The assessment of blood pressure (BP) in individuals is traditionally based on a few BP readings obtained at intervals of just a few minutes. We examined if increasing intervals between BP readings on one visit would have an impact on the BP estimates.

METHODS

We conducted an examination survey of cardiovascular risk factors in the general population aged 25-64 years in Seychelles (Indian Ocean), attended by 1255 of 1565 eligible participants. BP was measured once shortly after participants' arrival to the study centers (BP1) and twice before discharge, 15-351 min later (BP2, BP3; separated by 2 min).

RESULTS

Mean (standard error) BP1 was 135.1 (0.7)/87.9 (0.4) mmHg, BP2: 130.7 (0.6)/85.1 (0.4) mmHg and BP3: 128.4 (0.6)/83.9 (0.3) mmHg. The difference in BP between the first and the last measurements (DeltaBP1-BP3) was, respectively, 5.8 (1.3)/2.6 (0.9) mmHg for a time interval between BP1 and BP3 of 15-60 min, 6.3 (0.5)/3.9 (0.3) mmHg for 61-120 min, 6.9 (0.6)/4.1 (0.4) mmHg for 121-240 min and 7.4 (0.7)/4.3 (0.5) mmHg for 241-351 min (P-trend for systolic/diastolic BP: 0.15/0.49). In multivariate analysis, both systolic and diastolic DeltaBP were associated with the initial BP level and the female sex but not with time (in minutes) between BP readings (for systolic/diastolic BP, P=0.12/0.34).

CONCLUSION

The decrease in subsequent BP readings obtained did not differ whether the time interval between BP measurements was larger or smaller than 1 h. This indirectly suggests that extending the time interval between repeated BP readings on one single visit is unlikely to be a valid, alternative strategy to the recommendation of gathering BP readings on several, separate visits to define hypertension.

The cost effectiveness of pharmacological smoking cessation therapies in developing countries: a case study in the Seychelles

OBJECTIVE

To examine the incremental cost effectiveness of the five first line pharmacological smoking cessation therapies in the Seychelles and other developing countries.

DESIGN

A Markov chain cohort simulation.

SUBJECTS

Two simulated cohorts of smokers: (1) a reference cohort given physician counselling only; (2) a treatment cohort given counselling plus cessation therapy.

INTERVENTION

Addition of each of the five pharmacological cessation therapies to physician provided smoking cessation counselling.

MAIN OUTCOME MEASURES

Cost per life-year saved (LYS) associated with the five pharmacotherapies. Effectiveness expressed as odds ratios for quitting associated with pharmacotherapies. Costs based on the additional physician time required and retail prices of the medications.

RESULTS

Based on prices for currently available generic medications on the global market, the incremental cost per LYS for a 45 year old in the Seychelles was 599 US dollars for gum and 227 dollars for bupropion. Assuming US treatment prices as a conservative estimate, the incremental cost per LYS was significantly higher, though still favourable in comparison to other common medical interventions: 3712 dollars for nicotine gum, 1982 dollars for nicotine patch, 4597 dollars for nicotine spray, 4291 dollars for nicotine inhaler, and 1324 dollars for bupropion. Cost per LYS increased significantly upon application of higher discount rates, which may be used to reflect relatively high opportunity costs for health expenditures in developing countries with highly constrained resources and high overall mortality.

CONCLUSION

Pharmacological cessation therapy can be highly cost effective as compared to other common medical interventions in low mortality, middle income countries, particularly if medications can be procured at low prices.

Improved smoking cessation in smokers given ultrasound photographs of their own atherosclerotic plaques

BACKGROUND

We examined whether making smokers aware that they had developed peripheral atherosclerosis would improve smoking cessation.

METHODS

Smokers selected from the general population were randomly allocated to undergo high-resolution B-mode ultrasonography of their carotid and femoral arteries. All smokers received quit-smoking counseling. Smokers with > or =1 atherosclerotic plaque were given two photographs of a plaque with a relevant explanation. Quit rates were assessed by telephone 6 months later.

RESULTS

Seventy-nine smokers did not undergo ultrasonography (A). Among the 74 smokers submitted to ultrasonography, 20 had no plaque (B) and 54 had > or =1 plaque (C). Quit rates were, respectively, 6.3, 5.0, and 22.2% in groups A, B, and C. Quit rates were higher in smokers submitted to ultrasonography (B + C vs A; P = 0.031) and in those receiving photographs (C vs A + B; P = 0.003). Smoking cessation was independently associated with intervention C (OR = 6.2; 95% CI = 1.8-21) and a white-collar job but not with age or gender.

CONCLUSIONS

Providing smokers with photographs demonstrating atherosclerosis on their own person was an effective adjunct to physician's advice to quit smoking. Since ultrasonography is used increasingly often in clinical practice for cardiovascular risk stratification, this can provide an additional opportunity and means to deter smokers from smoking.

Prevalence and risk factors for overweight and obesity in children from Seychelles, a country in rapid transition: the importance of early growth

OBJECTIVES

To establish the prevalence of overweight and obesity and related risk factors in children from Seychelles (Indian Ocean), a country in rapid economic and epidemiological transition.

DESIGN

Cross-sectional study with retrospective access to early life data.

SUBJECTS

All children from all schools of Seychelles, in four selected school grades (kindergarten, fourth, seventh and tenth year of obligatory school) in 1999. A total of 5514 children aged 4.5-17.4 y were measured, corresponding to 83.5% of the eligible population.

MEASUREMENTS

Overweight and obesity, using age- and sex-specific body mass index (BMI) cut-off points as defined by the International Obesity Task Force.

RESULTS

Some 12.6% (95% confidence interval: 11.8-13.5%) of the children were overweight and 3.8% (3.3-4.4%) were obese. Weight gain (kg) during the first year of life was strongly associated with subsequent overweight (odds ratio 1.46, 95% confidence interval 1.27-1.67) and obesity (1.59, 1.29-1.97) in childhood, independently of birth weight. Increased maternal BMI (kg/m(2)) was also associated with overweight (1.07, 1.03-1.10) and obesity (1.09, 1.04-1.14) in the offspring.

CONCLUSION

Prevalence of overweight and obesity among school children in Seychelles was as high as or higher than in some industrialized countries. If confirmed in other environments, the strong association between weight gain during the first year of life and subsequent obesity in childhood could affect the way optimal infant weight gain is defined in countries where public health priorities are changing.

Apolipoprotein B as the best predictor of coronary artery disease in Iranian normolipidemic patients

OBJECTIVES

A relatively high proportion of Iranian patients with coronary artery disease (CAD) have normal levels of traditional lipid risk factors and show early onset of CAD. In this study we examined the roles of apolipoprotein B (apoB), apolipoprotein AI (apoAI) and lipoprotein (a) [LP(a)] in predicting coronary heart disease in normolipidemic patients and those with premature CAD (age < or = 50).

DESIGN AND METHODS

Serum levels of apoB, apoAI, and LP(a) were determined in a total of 567 Iranian patients who were candidates for coronary angiography. A subgroup of 142 patients (93 males, 49 females) with normal levels of classical lipid risk factors, and a subgroup of patients (130 males, 71 females) with age below 50 years were separately assessed for coronary risk factors.

RESULTS

ApoB concentrations were significantly higher in patients with CAD (CAD+) relative to patients without CAD (CAD-) in the two subgroups. Multiple logistic regression after controlling for age and others risk factors showed apoB as the best determinant of CAD in the normolipidemic subgroup (OR, 4.3, p < 0.001) and in the men aged < or = 50 (OR, 5.7, p < 0.001). ApoB was the best predictor of CAD in a subgroup of very young patients (age < or = 40, n = 77, OR, 8.6, p < 0.009). There was a significant correlation between severity of atherosclerosis and serum apoB concentration in the normolipidemic subgroup (r = 0.22, p < 0.008).

CONCLUSIONS

Our data indicate that serum concentration of apoB is the best discriminating factor to predict the presence or absence of atherosclerosis in Iranian normolipidemic individuals and young patients undergoing coronary angiography.