Comparison of cardiovascular disease risk factors, assessment and management in men and women, including consideration of absolute risk: a nationally representative cross-sectional study

Abstract

Objectives: Cardiovascular disease (CVD) is highly preventable and optimal treatments based on absolute risk can halve risk of future events. Compared with women, men have higher risks of developing CVD. However, women can experience suboptimal treatment. We aimed to quantify sex differences in CVD risk, assessment and treatment in Australian adults.

Design, participants, setting: Cross-sectional analysis of nationally representative data from interview, physical measures, medication review and blood and urine samples, from 2011 to 2012 Australian Health Survey participants aged 45-74 (n=11 518).

Outcome measures: CVD risk factors, absolute 5-year risk of a primary CVD event, blood pressure and cholesterol assessment in the previous 2 and 5 years and use of recommended CVD preventive medications were compared using Poisson regression to estimate age-adjusted male versus female prevalence ratios (PRs).

Results: Women had a generally more favourable CVD risk factor profile than men, including lower: current smoking prevalence (women=14.5%; men=18.4%, PR=0.78, 95% CI=0.70 to 0.88); body mass index (women (mean)=28.3 kg/m²; men (mean)=28.8 kg/m², p<0.01); systolic and diastolic blood pressure (systolic: women (mean)=127.1 mm Hg; men (mean)=130.5 mm Hg, p<0.001); blood glucose (women (mean)=5.2 mmol/L; men (mean)=5.5 mmol/L); diabetes prevalence (women=6.8%; men=12.5%, PR=0.55, 95% CI=0.44 to 0.67); prior CVD (women=7.9%; men=11.3%) and absolute primary CVD risk (absolute 5-year CVD risk >15%: women=6.6%, 95% CI=5.4 to 7.8; men=15.4%, 95% CI=13.9% to 16.9%). Compared with men, women had higher low-density lipoprotein, high-density lipoprotein and total cholesterol and sedentary behaviour and lower physical activity. Blood pressure and cholesterol assessment were common in both sexes. Among those at high absolute risk, age-adjusted proportions receiving recommended CVD medications were low, without sex differences (women=21.3%; men=23.8%, PR=0.93, 95% CI=0.49 to 1.78). Fewer women than men with prior atherosclerotic CVD were receiving recommended treatment (women=21.8%, men=41.4%, PR=0.55, 95% CI=0.31 to 0.96).

Conclusion: Women have a more favourable CVD risk factor profile than men. Preventive treatment is uncommon and women with prior atherosclerotic CVD are around half as likely as men to be receiving recommended treatment.

Keywords: coronary heart disease; epidemiology; public health.

Figure 1

Distribution of CVD risk factors in the Australian population aged 45–74 years, by sex. BMI, waist circumference, systolic blood pressure and diastolic blood pressure were measured as part of the core content for the Australian Health Survey (n=11 518). Proportion of missing values: BMI: 15.9%; waist circumference: 16.0%; systolic blood pressure: 15.3%; diastolic blood pressure: 15.3%. LDL, HDL and total cholesterol, and triglycerides, fasting plasma glucose and HbA1c were measured as part of the National Health Measures Survey (n=5253). Proportion of missing values: LDL cholesterol: 20.6%; HDL: 0.7%; total cholesterol 0.7%; triglycerides: 19.4%; fasting plasma glucose: 19.4%; HbA1c: 0.9%. All estimates have been weighted to be representative of the Australian population living in non-very remote areas. The x-axis for waist circumference is estimated with the difference between waist circumference and the sex-specific cut points for an ‘at risk’ waist circumference (80 cm for women, 94 cm for men). Body mass index and waist circumference are rounded to the nearest whole number. Systolic and diastolic blood pressure are rounded to the nearest second number. Risk factor values with less than 10 respondents have been suppressed. BMI, body mass index; HbA1c, haemoglobinA1c; HDL, high-density lipoprotein; LDL, low-density lipoprotein.

Figure 2

Age-adjusted prevalence, prevalence difference and prevalence ratios (and 95% CI) for CVD risk factors for the population aged 45–74 years for women versus men. Prevalence differences and prevalence ratios compare women to men. The prevalence ratio is plotted. BMI, waist circumference, systolic blood pressure and diastolic blood pressure were measured as part of the core content for the Australian Health Survey (n=11 518). Proportion of missing values: BMI: 15.9%; waist circumference: 16.0%; systolic blood pressure: 15.3%; diastolic blood pressure: 15.3%. LDL, HDL, total and total: HDL cholesterol, triglycerides, fasting plasma glucose, HbA1c, diabetes, diabetes with microalbuminuria and chronic kidney disease were measured as part of the National Health Measures Survey (n=5253). Proportion of missing values: LDL cholesterol: 20.6%; HDL: 0.7%; total cholesterol 0.7%; total: HDL cholesterol: 0.7%; triglycerides: 19.4%; fasting plasma glucose: 19.4%; HbA1c: 0.9%; diabetes and diabetes with microalbuminuria: 0.9%; chronic kidney disease: 0.8%. All estimates have been weighted to be representative of the Australian population living in non-very remote areas. An at-risk waist circumference is defined as ≥80 cm for women and ≥94 cm for men. BMI, body mass index; BP, blood pressure; CVD, cardiovascular disease; HbA1c, haemoglobinA1c; HDL, high-density lipoprotein; LDL, low-density lipoprotein.

Figure 3

Estimated distribution of 5 year absolute CVD risk, including clinically high risk and prior CVD, among the Australian population aged 45–74 years, by sex. Estimates are based on 4833 people who participated in the National Health Measures Survey with no missing data on variables needed to calculate absolute CVD risk. All estimates have been weighted to be representative of the Australian population living in non-very remote areas. CVD, cardiovascular disease.

Figure 4

Estimated proportions in the Australian population aged 45–74 years using cardiovascular disease medications for those at low, moderate and high primary CVD risk and those with prior atherosclerotic/thromboembolic CVD, by sex. Estimates are based on 2847 people who participated in the National Health Survey and the National Health Measures Survey and had enough information to estimate absolute CVD risk. All estimates have been weighted to be representative of the Australian population living in non-very remote areas. No medication refers to no blood pressure-lowering, lipid-lowering or antithrombotic medications. Proportions receiving blood pressure-lowering and lipid-lowering and antithrombotic medication among those at low or moderate absolute risk of primary CVD have been suppressed due to small cell sizes. CVD, cardiovascular disease.