Yu Bin, Chen Xinguang, Lu Dandan, Yan Hong, Wang Peigang
Department of Epidemiology and Health Statistics, School of Public Health, Wuhan University, Wuhan, China.
Population and Health Research Center, Wuhan University, Wuhan, China.
Front Cardiovasc Med. 2022 Aug 17;9:948561. doi: 10.3389/fcvm.2022.948561. eCollection 2022.
Obesity as a risk factor of heart disease (HD) is confirmed through observational, laboratory, and intervention studies. However, it cannot explain why HD declines, but obesity increases in the United States in recent decades. This study attempted to understand this paradox.
Annual data of national HD mortality (1999-2018) were derived from Wide-Ranging Online Data for Epidemiologic Research, biannual obesity data (1999-2016) from the National Health and Nutrition Examination Survey, and smoking data (1965-1990) were from the National Health Interview Survey. Age-period-cohort method was used to decompose HD mortality into age, period, and cohort effects, and to estimate age-cohort adjusted mortality rates. To explain the paradox, age-cohort adjusted rates were associated with obesity rates to verify the positive obesity-HD relationship, while smoking rates were associated with cohort effects to explain the current declines in HD mortality.
During 1999-2018, the prevalence of obesity increased while the crude HD mortality rate declined for both sex and all races. After controlling for the curvilinear age effect and consistent declining cohort effect, the age-cohort adjusted HD mortality sustained stable in 1999-2007 and increased thereafter. The age-cohort adjusted rate in 1999-2018 (per 100,000) increased from 189.31 to 238.56 for males, 67.23 to 90.28 for females, 115.54 to 157.39 for White, 246.40 to 292.59 for Black, 79.79 to 101.40 for Hispanics, and 49.95 to 62.86 for Asian. The age-cohort adjusted HD mortality rates were positively associated with obesity rates ( = 0.68 for males, 0.91 for females, 0.89 for White, and 0.69 for Hispanic, < 0.05), but not significant for Black and Asian. Further, during 1965-1990, the estimated cohort effect showed a decline in HD risk and was positively associated with smoking rates ( = 0.98 for both sex, 0.99 for White, and 0.98 for Black, < 0.01).
Study findings reveal potential increase of HD risk and support the positive relationship between obesity and HD risk. Declines in HD mortality in the past two decades are primarily due to tobacco use reduction and this protective effect was entangled in the mortality rates as cohort effect.
肥胖作为心脏病（HD）的一个风险因素已通过观察性、实验室和干预性研究得到证实。然而，它无法解释为何在美国近几十年来心脏病死亡率下降而肥胖率却上升。本研究试图理解这一矛盾现象。
1999 - 2018年全国心脏病死亡率的年度数据来自流行病学研究的广泛在线数据，1999 - 2016年肥胖的半年数据来自国家健康与营养检查调查，吸烟数据（1965 - 1990年）来自国家健康访谈调查。采用年龄 - 时期 - 队列方法将心脏病死亡率分解为年龄、时期和队列效应，并估计年龄 - 队列调整死亡率。为解释这一矛盾，将年龄 - 队列调整率与肥胖率相关联以验证肥胖与心脏病之间的正向关系，同时将吸烟率与队列效应相关联以解释当前心脏病死亡率的下降。
在1999 - 2018年期间，肥胖患病率上升，而所有性别和种族的心脏病粗死亡率均下降。在控制了曲线年龄效应和持续下降的队列效应后，1999 - 2007年年龄 - 队列调整后的心脏病死亡率保持稳定，此后上升。1999 - 2018年男性年龄 - 队列调整率（每10万人）从189.31升至238.56，女性从67.23升至90.28，白人从115.54升至157.39，黑人从246.40升至292.59，西班牙裔从79.79升至101.40，亚裔从49.95升至62.86。年龄 - 队列调整后的心脏病死亡率与肥胖率呈正相关（男性 = 0.68，女性 = 0.91，白人 = 0.89，西班牙裔 = 0.69，P < 0.05），但对黑人和亚裔不显著。此外，在1965 - 1990年期间，估计的队列效应显示心脏病风险下降，且与吸烟率呈正相关（两性均为 = 0.98，白人 = 0.99，黑人 = 0.98，P < 0.01）。
研究结果揭示了心脏病风险可能增加，并支持肥胖与心脏病风险之间的正向关系。过去二十年中心脏病死亡率的下降主要归因于吸烟减少，这种保护作用作为队列效应体现在死亡率中。
