Association between baseline levels of muscular strength and risk of stroke in later life:The Cooper Center Longitudinal Study

Background:Muscular strength is an important component of physical fitness.We evaluated the relationship between baseline muscular strength and risk of stroke among adults who were aged≥65 years during follow-up.Methods:We included 7627 healthy adults(mean age=43.9 years,86.0%male)underwent a baseline physical examination between 1980 and 1989.Muscular strength was determined by 1-repetition maximum measures for bench press and leg press and categorized into age-and sex-specific tertiles for each measure.Cardiorespiratory fitness(CRF)was assessed via a maximal treadmill exercise test.Those enrolled in fee-for-service Medicare from 1999 to 2019 were included in the analyses.Associations between baseline strength and stroke outcomes were estimated using a modified Cox proportional hazards model.In a secondary analysis,we examined stroke risk by categories of CRF where Quintile 1=low,Quintiles 2-3=moderate,and Quintiles 4-5=high CRF based on age and sex.Results:After 70,072 person-years of Medicare follow-up,there were 1211 earliest indications of incident stroke.In multivariable analyses,the hazard ratio(95%confidence interval(95%CI))for stroke across bench press categories were 1.0(referent),0.96(0.83-1.11),and 0.89(0.77-1.04),respectively(p trend=0.14).The trend across categories of leg press was also non-significant(p trend=0.79).Adjusted hazard ratio(95%CI)for stroke across ordered CRF categories were 1.0(referent),0.90(0.71-1.13),and 0.72(0.57-0.92)(p trend<0.01).Conclusion:While meeting public health guidelines for muscular strengthening activities is likely to improve muscular strength as well as many health outcomes in older adults,performing such activities may not be helpful in preventing stroke.Conversely,meeting guidelines for aerobic activity is likely to improve CRF and lower stroke risk.

库珀中心纵向研究:有氧运动的灵魂

目的:为肯尼斯·库珀(Kenneth H. Cooper)于1970年提出的库珀中心纵向研究(CCLS)提供详细历史。方法:对库珀中心纵向研究人群和库珀诊所所检查的重要参数,以及库珀诊所患者的各种疾病发病率和死亡率进行数据描述。并对近50年来已发表的库珀中心纵向研究的主要研究结果进行总结。结果:在库珀诊所检查期间,通过最大跑台运动测试客观地测量出的心肺功能(CRF)已成为各种疾病发病率和死亡率的强大且独立的风险因素。更具体地说,库珀中心纵向研究明确表明,中高水平的心肺功能与人体全因、心血管疾病和癌症死亡率有显著相关关系。此外,已经证明,中年人群的心肺水平是全因痴呆、Ⅱ型糖尿病、慢性肾病、癌症发病率和存活率以及一些其他慢性疾病的预测因子。因此,库珀中心纵向研究结果还表明,中年人群的心肺水平与老年时期的医疗保健成本呈显著相关。结论:除罕见情况以外,已经进行了近50年的库珀中心纵向研究的研究结果表明,相对于较低水平的心肺功能,中高水平的心肺功能可以有效预防许多疾病。

Cardiorespiratory fitness,white blood cell count,and mortality in men and women

Background:We examined the associations of cardiorespiratory fitness(CRF) and white blood cell count(WBC) with mortality outcomes.Methods: A total of 52,056 apparently healthy adults completed a comprehensive health examination,including a maximal treadmill test and blood chemistry analyses.CRF was categorized as high,moderate,or low by age and sex;WBC was categorized as sex-specific quartiles.Results:During 17.8± 9.5 years(mean± SD) of follow-up,a total of 4088 deaths occurred.When regressed jointly,significantly decreased allcause mortality across CRF categories was observed within each quartile of WBC in men.Within WBC Quartile 1,all-cause mortality hazard ratios(HRs) with a 95% confidence interval(95%CI) were 1.0(referent),1.29(95%CI:1.06-1.57),and 2.03(95%CI:1.42-2.92) for high,moderate,and low CRF categories,respectively(p for trend <0.001).Similar trends were observed in the remaining 3 quartiles.With the exception of cardiovascular disease(CVD) mortality within Quartile 1(p for trend=0.743),there were also similar trends across CRF categories within WBC quartiles in men for both CVD and cancer mortality(p for trend <0.01 for all).For women,there were no significant trends across CRF categories for mortality outcomes within Quartiles 1-3.However,we observed significantly decreased all-cause mortality across CRF categories within WBC Quartile 4(HR=1.05(95%CI:0.76-1.44),HR=1.63(95%CI:1.20-2.21),and HR=1.87(95%CI:1.29-2.69) for high,moderate,and low CRF,respectively(p for trend=0.002)).Similar trends in women were observed for CVD and cancer mortality within WBC Quartile 4 only.Conclusion:There are strong joint associations between CRF,WBC,and all-cause,CVD,and cancer mortality in men;these associations are less consistent in women.