Atherosclerotic Cardiovascular Disease Novel and Traditional Risk Factors in Middle Eastern Young Women. The ANCORS-YW Study

Study design

A case-control, multicenter study was conducted in the period between August 2021 and October 2023 in 12 hospitals. Each patient with ASCVD was age-matched (±5 years) with two women controls selected from the same population in each center participating in enrolling case for the study. Specifically, they included health care centers’ workers, visitors and patients’ companions. These women did not have a prior diagnosis of ASCVD, and were free of symptoms suggestive of this disease. The investigators in each center were instructed, once a patient was enrolled, to select two control women fulfilling the above criteria.

Anthropometric and demographic profiles, novel and traditional risk factors, and SDOH (place of residence, level of education, and presence of health insurance) of the patients and controls were documented based on measurements by the interviewing study investigators according to a unified standard protocol.

With a significance level of 0.05, a power of 80%, and assuming a frequency of any one of the studied variables to be 10%, we have calculated the minimum sample size required to detect a clinically significant association (odds ratio = 2) between ASCVD and any of the studied predictors, maintaining a 1:2 case-to-control ratio. The computed sample size was 209 cases and 418 controls.

Inclusion criteria

Women in the case group were enrolled in the study if they have ASCVD, were aged 18–50 years, were married, had at least one pregnancy, and were willing to sign an informed consent. Women in the control group were enrolled if they fulfilled the same criteria as women in the case group but do not have ASCVD.

Definition of exposures

ASCVD included acute coronary syndrome (ACS) (ST-segment elevation MI, non-ST-segment elevation MI, and unstable angina), coronary artery disease (CAD) diagnosed by coronary computed tomographic angiography, stroke and transient ischemic attack (diagnosed by a neurologist based on standard clinical and imaging criteria), extracranial carotid artery disease (diagnosed by the presence of atherosclerosis of the common or internal carotid artery evident by arterial Doppler, computed tomographic, or invasive angiography), and peripheral arterial disease (PAD) of the lower extremities (lower extremity ischemic pain and/or atherosclerosis evident by arterial Doppler, computed tomographic, or invasive angiography).

Definitions of traditional risk factors

Hypertension (HTN) was defined as repeated resting blood pressure (BP) measurements ≥140/90 mm Hg, a prior diagnosis by a treating physician, or use of BP medications. T2D was defined as the presence of classical symptoms of hyperglycemia and casual plasma glucose ≥200 mg/dl, fasting plasma glucose ≥126 mg/dl, serum level of glycated hemoglobin ≥6.5 g/dl, or a prior diagnosis by a treating physician. Dyslipidemia was defined as an elevated serum level of low-density lipoprotein cholesterol (LDL-C) >70 mg/dl in those with ASCVD or T2D, and >116 mg/dl in those with no ASCVD or T2D. Low serum level of high-density lipoprotein cholesterol (HDL-C) was defined as serum levels <50 mg/dl. Body mass index was calculated by the standard formula (weight (kg)/height (m²)). Diagnosis of metabolic syndrome was confirmed by the presence of at least three of the following criteria: HTN, obesity (BMI ≥ 30 kg/m²), serum level of HDL-C <50 md/dl, and serum level of triglycerides >150 mg/dl.

Definitions of novel risk factors

Preterm delivery was defined as a live delivery before 37 weeks and after 20 weeks of gestation. Hypertensive disorders of pregnancy (HDP) was defined as any of gestational HTN (occurring for the first time after 20 weeks of gestation with no significant proteinuria or other biochemical or hematological abnormalities), chronic HTN (diagnosed before the 20th week of gestation), pre-eclampsia defined as HTN after the 20th week of gestation associated with significant proteinuria or evidence of other biochemical or hematological abnormalities) and eclampsia (defined as seizures not attributable to other causes in the presence of preeclampsia).

Gestational diabetes mellitus (GDM) was diagnosed if one or more of the following criteria are met: fasting plasma glucose ≥126 mg/dl, 2-h plasma glucose ≥200 mg/dl following a 75 g oral glucose load, and random plasma glucose ≥200 mg/dl in the presence of diabetes symptoms.

Weight gain after pregnancy was defined according to the Institute of Medicine criteria [8] and refers to weight retention 12 months after delivery as gaining more than 16 kg in women with a normal pre-pregnancy BMI, gaining more than 11 kg in those who were overweight prior to pregnancy, or gaining more than 9 kg in those who were obese prior to pregnancy.

Polycystic ovary syndrome (PCOS) was defined by the presence of two clinical or biochemical hyperandrogenism features, ovulatory dysfunction, or polycystic ovaries. Premature menopause was defined as oligo-amenorrhea of more than 12 months associated with serial elevated gonadotropins on three occasions measured 4–6 weeks apart in women under the age of 40 years. Depression was defined as prior diagnosis by a psychiatrist, or prescription of antidepressant medication.

The centers that participated in the study enrolled equal proportion (8–11%) of the whole cohort. The definition of ASCVD was uniform and was used by all centers. Although treatment of ASCVD was according to discretion of the treating cardiologist, such therapeutic strategies followed the current practice guidelines. All of the participating hospitals were tertiary care centers with 24/7 cardiac catheterizations services.

This non-interventional study has been performed in accordance with the Declaration of Helsinki. The study received proper ethical oversight and Institutional Review Board approval from the participating institutions (Institutional Review Board/Independent Ethics Committee Istishari hospital, Amman, Jordan, Approval number IH-IRB-IRC-7-29-2021). Each patient signed a written informed consent. The study is registered with ClinicalTrials.gov (NCT04975503).

Statistical analysis

Data were analyzed using IBM SPSS Statistics version 24. Descriptive statistics were performed using means and standard deviation (SD) to describe the continuous variables and proportions to describe the categorical variables. Independent t-test was used to compare means and chi-square test was used to compare percentages of the variables in women with ASCVD and those who have no ASCVD. Binary logistic regression analysis was conducted to determine factors associated with ASCVD. A p-value of less than 0.05 was considered statistically significant.

Results

Of the 627 women enrolled, 209 had ASCVD, and 418 served as controls. Comparison of the anthropometric, demographic, socioeconomic and clinical features of the ASCVD and control groups are shown in Table 1. The majority (eight in ten) of women in both groups were 40–50 years of age. Women in the ASCVD group were less likely to have received graduate or post graduate education. More women with ASCVD had health insurance compared with the control group. Urban or rural residence did not significantly differ in both groups.

Five traditional risk factors (HTN, T2D, cigarette smoking, FHx, and elevated LDL-C) were more prevalent in young women with ASCVD than the control group (Table 1 and Figure 1). Serum levels of LDL-C and HDL-C were available for 62% and 29% of the ASCVD and control groups, respectively. Mean LDL-C in the ASCVD group was 112 ± 34.7 mg/dl, and 10.0% of those had an LDL-C of >190 mg/dl. High levels of LDL-C and low levels of HDL-C were more prevalent in the ASCVD group. Prevalence rates of obesity and physical inactivity were not different between the two groups.

Figure 1

Of all novel risk factors studied (Table 1 and Figure 2), preterm delivery, HDP, and GDM were more prevalent in the ASCVD group than the control group. The higher prevalence of HDP in women with ASCVD was mainly driven by chronic HTN, rather than preeclampsia and gestational HTN. No significant differences were demonstrated between the two groups in the prevalence rates of premature menopause, PCOS, breast cancer, depression, or autoimmune disease.

Figure 2

Details of the diagnosed ASCVD are shown in Table 2. The majority (86%) of patients had CAD, and 95% of those had ACS too. Percutaneous or surgical coronary revascularization was undertaken in around 70% of those who had ACS. Around one in five women had a stroke, and only 8% had multiarterial bed involvement (≥2 of the coronary, carotid, and peripheral arterial disease).

Prescribed medications for both groups are shown in Table 3. All secondary preventive medications, including oral antiplatelet agents, statins, and beta blocker were prescribed for the majority, and renin-angiotensin system inhibitors for nearly half of the patients with ASCVD. The mean blood pressure (mmHg) readings in the patient and control groups at baseline were 133/81 vs. 131/79, respectively, p = 0.15. Compared to women in the control group, more women with ASCVD were prescribed one antihypertension medication (37.8% vs. 23.7%, p < 0.001), or two medications (38.3% vs. 5.5%, p < 0.002), respectively. Three medications were prescribed in similar proportions for both groups (6.2% vs. 3.3%, p = 14).

Multivariable analyzes utilizing 17 variables (6 traditional risk factors, and 11 novel and psychosocial risk factors), demonstrated that four traditional (HTN, T2D, FHx, and cigarette smoking), and one novel risk factor (persistent weight gain after pregnancy) were independently associated with ASCVD (Supplement Table and Table 4). The Multivariable analyzes did not include LDL-C or HDL-C (and subsequently, metabolic syndrome) because lipoprotein cholesterol serum levels were not available for all participating women.

Traditional risk factors

Not unexpectedly, the study demonstrated a robust association between most of traditional risk factors and ASCVD in the population under consideration. Global cohorts of women and men showed that significant portion of incident ASCVD and all-cause deaths may be attributable to traditional risk factors [1, 2, 3]. In the Middle East, traditional risk factors, including HTN, T2D, cigarette smoking, obesity, dyslipidemia, and FHx have stronger association with ASCVD in both sexes of all age groups, and our study confirmed this association in young women as well [7, 11, 12].

In addition to the fact that traditional risk factors were more prevalent in young women with ASCVD, the study demonstrated an alarmingly high prevalence rates of these risk factors in young women in the control group as well. These rates are higher than those reported from western and South East Asian populations, particularly HTN, T2D, LDL-C levels, cigarette smoking, obesity, and physical inactivity [12, 13]. Physical inactivity and sedentary behaviors remain a worldwide concern despite the proven cardioprotective role of regular exercise in the primary and secondary prevention of ASCVD [14]. The majority of women in the current study in both the ASCVD and control groups did not exercise on regular basis, probably a reflection of social factors that might limit widespread participation of women in outdoors physical activities in some local communities.

Novel risk factors

The list of sex-specific risk factors shown to have strong association with ASCVD in young women is large and expanding. It includes, in addition to the risk factors examined in the current study, early menarche, intrauterine growth retardation, abortion, still birth, earlier age at first birth, low- or high-birth weight fetus, short reproductive life span, hypothalamic amenorrhea, oral contraceptives, and hormone replacement [2, 4, 5, 15]. The current study demonstrated a significantly higher prevalence of three novel risk factors in women with ASCVD (HDP, GDM, and preterm delivery), and only one other risk factor (persistent weight gain after pregnancy) being independently associated with ACSV on multivariate analysis.

Approximately 30% of women experience an adverse pregnancy outcome (APO), including HDP, preterm delivery, and GDM [16]. The long term (7–10 years) association of multiple novel risk factors with ASCVD was ≥2-fold or greater for pre-eclampsia, GDM, and preterm birth; 1.5–1.9-fold for premature ovarian insufficiency, and early menopause; and <1.5-fold for PCOS [9, 15, 16]. Despite the potential influence by residual confounding on the association of APO with ASCVD, recent evidence has demonstrated a causal genetic relevance of reproductive factors on ASCVD in women [17]. Some authorities advocate considering the sex-specific risk factors to be used for ASCVD risk stratification and prevention programs in women [16].

The current study showed a significantly higher prevalence of HDP in women with ASCVD which was mainly driven by the higher prevalence of chronic HTN, not gestational HTN, or preeclampsia. HDP, and pre-eclampsia in particular, is a major cause of maternal and perinatal morbidity and mortality, and has a fourfold and threefold increased risk of AMI and stroke, respectively, than women without pre-eclampsia ten years after delivery [18]. Multiple pathophysiological mechanisms might explain this association, including a high inflammatory milieu, anti-angiogenic state, and high blood levels of atherogenic lipids. These changes lead to endothelial dysfunction, lower coronary flow reserve, higher carotid intima-media thickness, subclinical atherosclerosis, arterial stiffness, and accelerated atherosclerosis [19].

The second novel risk factor with significantly higher prevalence in women with ASCVD in this study was GDM. Globally, the prevalence of GDM was estimated at 14.0%, and the prevalence in low-, middle- and high-income countries ranges between 9.2 and 14.2%. There is a two-fold higher risk of subsequent overall cardiovascular diseases in women with a history of GDM than women without GDM. [20]. Pathophysiological plausibility for the relationship between GDM and ASCVD are diverse and includes insulin resistance, elevated levels of LDL-C and triglycerides, low levels of HDL-C, and circulating inflammatory markers which increase the risk of T2D, HTN, and metabolic syndrome [20].

Spontaneous preterm delivery had also significantly higher prevalence in young women with ASCVD than controls. Preterm delivery, which occurs in 5–13% of deliveries globally, is an independent risk factor for long term cardiovascular mortality. It represents a proinflammatory and microvascular disease associated with higher circulating levels of C-reactive protein levels, endothelial dysfunction, genetic mutations of cholesterol metabolism, and subclinical vascular disease. Consequently this leads to 1.4- to 2-fold risk of ASCVD [21].

Persistent weight gain after pregnancy was the only independent novel factor to be associated with ASCVD. Several pregnancy and postpartum weight change trajectories have been identified. After weight gain during pregnancy and immediate weight loss after delivery, some women continue to lose weight, while others regain gestational weight. Several factors lead to failure to restore the pre-pregnancy body weight, such as the maternal age and BMI, parity, dietary changes, lack of time for exercise, decrease in sleep hours, and psychological stress [22].

Premature menopause was reported by ≤10% of the whole cohort in this study, with no significant differences between women with ASCVD and controls. Spontaneous or iatrogenic premature ovarian failure and menopause in young women is associated with a two-fold risk of ASCVD and driven by the diminishing cardioprotective effects of estrogen that include endothelial dysfunction, dyslipidemia, dysglycemia, and metabolic syndrome [23].

This study reported a similar prevalence of PCOS (6.7%) in patients and controls, a rate not different from the global estimated prevalence rate that ranges between 4% and 21% of women before menopause [24]. PCOS is the most common endocrine disorder among women of reproductive age and is associated with several cardiometabolic abnormalities, including obesity, T2D, HTN, and dyslipidemia, and with an increased risk of an increased risk of subclinical atherosclerosis, CAD, and stroke [25]. Recently, Mendelian randomization studies have challenged the causality of PCOS with CAD and stroke [26].

Breast cancer, reported by only 5 (1.2%) women in this study, has been shown by many investigators to increase the risk of ASCVD up to at least two decades especially in women with left breast cancer, those who received high dose of radiation, and those who have classical ASCVD risk factors [27]. The other disease with low incidence in women enrolled in this study was the autoimmune group of disease and reported in 31 (4.9%) women. Systemic inflammatory and autoimmune disorders (including systemic lupus, rheumatoid arthritis, scleroderma, vasculitis, and psoriasis) affect more women than men and are associated with accelerated atherosclerosis likely related to a variety of factors including the coexistence of other risk factors and their duration, lifestyle habits and practices, sex hormone effects, immune dysregulation, and systemic inflammation [28].

Other risk factors

In addition to the traditional and novel risk factors, certain non-sex-related SDOH and psychological factors have also been linked to ASCVD in young women. SDOH describe the living and working environment of individuals and includes five domains (education, health insurance, neighborhood and environment, economic stability, and social and community context) [29]. The first three of these domains were addressed in the current study. While the great majority of the whole cohort received at least a school education (n = 623, 99.4%), more women in the control group attended college and postgraduate education than women with ASCVD. Studies have demonstrated a negative association between education level and prevalence of ASCVD because higher education level enhances the woman’s ability to make better informed health decisions, seek early and regular health advice, and adhere to prescribed therapies [30]. Concerning the place of residence, we did not find a difference in the place of residence (i.e., urban vs. rural) between the two groups of women. Excess CVD risk burden among urban young women parallels the growing burden of cardiometabolic risk factors such as HTN, T2D, obesity, and physical inactivity [31]. Finally, depression was reported by a similar percentage of patients and controls in this study. Among 35 studies involving about 1 million individuals, depression was associated with increased risk of ASCVD [32].

It is imperative to note that the process of recruiting women in the control group is of paramount importance in this case-control study to ensure reliability of the conclusions reached. The potential biases resulting from the conduction and methodology of the recruitment process of controls may influence the results of the study and their interpretation. Such biases include inaccurate data recall by interviewed women, failure to enroll consecutive patients, and failure to ascertain absence of symptoms that may implicate an undiagnosed ASCVD. Minimizing such biases in the current study relied on the fact that it is a restricted study that involves consecutive women exclusively, and controls were age-matched with patients, and were recruited from the same social environment as that of the patients’. Limiting confounding by utilization of this restriction and selection strategy was enhanced by enrolling more controls (i.e., 2 to 1 matching of controls to patients). Furthermore, the majority of the women in the control group (87.8%) were visitors in the recruiting centers, rather than health care workers (5.3%) or patients’ companions (6.9%). Relying on personal interviews with controls, as opposed to self-reporting questionnaire, further augments the reliability and strengthens the validity of the study conclusions.