The role of overweight and obesity in adverse cardiovascular disease mortality trends: an analysis of multiple cause of death data from Australia and the USA

Abstract

Background: In recent years, there have been adverse trends in premature cardiovascular disease (CVD) mortality rates (35-74 years) in the USA and Australia. Following long-term declines, rates in the USA are now increasing while falls in Australia have slowed rapidly. These two countries also have the highest adult obesity prevalence of high-income countries. This study investigates the role of overweight and obesity in their recent CVD mortality trends by using multiple cause of death (MCOD) data-direct individual-level evidence from death certificatesand linking the findings to cohort lifetime obesity prevalence. Methods: We identified overweight-and obesity-related mortality as any CVD reported on the death certificate (CVD MCOD) with one or more of diabetes, chronic kidney disease, obesity, lipidemias or hypertensive heart disease (DKOLH-CVD), causes strongly associated with overweight and obesity. DKOLH-CVD comprises 50% of US and 40% of Australian CVD MCOD mortality. Trends in premature age-standardized death rates were compared between DKOLH-CVD and other CVD MCOD deaths (non-DKOLH-CVD). Deaths from 2000 to 2017 in the USA and 2006-2016 in Australia were analyzed. Trends in in age-specific DKOLH-CVD death rates were related to cohort relative lifetime obesity prevalence. Results: Each country's DKOLH-CVD mortality rate rose by 3% per annum in the most recent year, but previous declines had reversed more rapidly in Australia. Non-DKOLH-CVD mortality in the USA increased in 2017 after declining strongly in the early 2000s, but in Australia it has continued declining in stark contrast to DKOLH-CVD. There were larger increases in DKOLH-CVD mortality rates at successively younger ages, strongly related with higher relative lifetime obesity prevalence in younger cohorts. Conclusions: The increase in DKOLH-CVD mortality in each country suggests that overweight and obesity has likely been a key driver of the recent slowdown or reversal of CVD mortality decline in both countries. The larger recent increases in DKOLH-CVD mortality and higher lifetime obesity prevalence in younger age groups are very concerning and are likely to adversely impact CVD mortality trends and hence life expectancy in future. MCOD data is a valuable but underutilized source of data to track important mortality trends.

The Impact of Morbid Obesity on the Health Outcomes of Hospital Inpatients: An Observational Study

“…The prevalence of morbid obesity according to this study was 6.1%, which is much lower than a United States (US) study [ 20 ] which included 800,417 hospitalised patients and found that 23.4% were morbidly obese. This discrepancy in the prevalence rates of morbid obesity in hospitalised patients between the two studies could partly be a reflection of in general a higher prevalence of obesity in US compared to Australia [ 28 ]. In addition, the discrepancy could be related to the differences in selection criteria between the two studies because the American study included only patients who were over the age of 40 years who were admitted with a diagnosis of cancer, chronic obstructive pulmonary disease (COPD), asthma and cardiovascular disease (CVD) compared to our inclusion of relatively younger patients presenting with a broader range of clinical diagnoses in our study.…”

Assessment of kidney function: clinical indications for measured GFR

“…The prevalence of patients with obesity [defined as a body mass index (BMI) ≥30 kg/m 2 ] is increasing worldwide. Obesity is associated with an increased incidence of cardiovascular disease, hypertension, diabetes mellitus, chronic kidney disease (CKD) and mortality [ 39 ]. Creatinine-based equations may overestimate GFR when used in individuals with a BMI >30 kg/m 2 due to variable body composition, including reduced muscle mass [ 40 ].…”

Association Between Obesity Grade and the Age of the First Acute Coronary Syndrome: Cross-sectional Observational Study

“…In the upper BMI range (25-50 kg/m 2 ), each 5 kg/m 2 higher BMI is associated with approximately 40% higher mortality in ischemic heart disease. Ischemic CAD is associated with lower life expectancy [1,31,32]. Therefore, initiating CV preventive treatment in patients with obesity at an earlier age is important.…”

“…Obesity is a highly preventable cause of death and an independent risk factor for cardiovascular diseases (CVD) [1]. Although cardiovascular (CV) events have decreased in the last 2 decades, premature atherosclerotic events have increased in younger individuals [2].…”