Iribarren C, Reed D M, Burchfiel C M, Dwyer J H
Department of Preventive Medicine, University of Southern California School of Medicine, Los Angeles 90033, USA.
JAMA. 1995 Jun 28;273(24):1926-32.
To further investigate the relationship between serum total cholesterol (TC) level and mortality due to major causes. In particular, is the elevated mortality among persons with low TC levels due to confounding conditions that both lower TC level and increase the risk of mortality, and is the association between low or high TC level and mortality homogeneous in the population or, alternatively, restricted to persons with other risk factors?
Prospective cohort study.
Free-living population in Oahu, Hawaii.
A total of 7049 middle-aged men of Japanese ancestry.
Age- and risk factor-adjusted mortality due to coronary heart disease, hemorrhagic stroke, cancer, chronic obstructive pulmonary disease, nonmalignant liver disease, trauma, miscellaneous and unknown, and all causes.
During 23 years of follow-up, a total of 1954 deaths were documented (38% cancer, 25% cardiovascular, and 37% other). Men with low serum TC levels (< 4.66 mmol/L [< 180 mg/dL]) were found to have several adverse health characteristics, including a higher prevalence of current smoking, heavy drinking, and certain gastrointestinal conditions. In an age-adjusted model, and in relation to the reference group (4.66 to 6.19 mmol/L [180 to 239 mg/dL]), those in the lowest TC group (< 4.66 mmol/L [< 180 mg/dL]) were at significantly higher risk of mortality due to hemorrhagic stroke (relative risk [RR], 2.41; 95% confidence interval [Cl], 1.45 to 4.00), cancer (RR, 1.41; 95% Cl, 1.17 to 1.69), and all causes (RR, 1.23; 95% Cl, 1.09 to 1.38). Adjustment for confounders in multivariate analysis (and exclusion of cases with prevalent disease at baseline and deaths through year 5) did not explain the risk of fatal hemorrhagic stroke but reduced the excess risk of cancer mortality by 51% (to 1.20 from 1.41) and reduced the excess risk of all-cause mortality by 56% (to 1.10 from 1.32) in the low TC group. In addition, there were clear differences in the patterns of risk when comparing men with and without selected risk factors (ie, smoking, alcohol consumption, and untreated hypertension).
We conclude that the excess mortality at low TC levels can be partially explained by confounding with other determinants of death and by preexisting disease at baseline, and TC-mortality associations are not homogeneous in the population. In our study, TC level was not associated with increased cancer or all-cause mortality in the absence of smoking, high alcohol consumption, and hypertension.
进一步研究血清总胆固醇（TC）水平与主要病因导致的死亡率之间的关系。特别是，低TC水平人群的死亡率升高是否是由于既降低TC水平又增加死亡风险的混杂因素所致，以及低或高TC水平与死亡率之间的关联在人群中是否一致，或者是否仅限于有其他危险因素的人群？
前瞻性队列研究。
夏威夷瓦胡岛的自由生活人群。
共7049名日本裔中年男性。
经年龄和危险因素调整后的冠心病、出血性中风、癌症、慢性阻塞性肺疾病、非恶性肝病、创伤、其他及不明原因以及所有原因导致的死亡率。
在23年的随访期间，共记录了1954例死亡（38%为癌症，25%为心血管疾病，37%为其他原因）。血清TC水平低（<4.66 mmol/L [<180 mg/dL]）的男性被发现有若干不良健康特征，包括当前吸烟、大量饮酒及某些胃肠道疾病的患病率较高。在年龄调整模型中，与参照组（4.66至6.19 mmol/L [180至239 mg/dL]）相比，TC水平最低组（<4.66 mmol/L [<180 mg/dL]）因出血性中风导致的死亡风险显著更高（相对风险[RR]，2.41；95%置信区间[CI]，1.45至4.00）、癌症（RR，1.41；95% CI，1.17至1.69）以及所有原因（RR，1.23；95% CI，1.09至1.38）。多变量分析中对混杂因素进行调整（并排除基线时患有现患疾病及随访5年内死亡的病例）并不能解释致命性出血性中风的风险，但低TC组中癌症死亡的额外风险降低了51%（从1.41降至1.20），全因死亡的额外风险降低了56%（从1.32降至1.10）。此外，在比较有和没有选定危险因素（即吸烟、饮酒和未治疗的高血压）的男性时，风险模式存在明显差异。
我们得出结论，低TC水平时的额外死亡率可部分由与其他死亡决定因素的混杂以及基线时的既有疾病来解释，且TC与死亡率之间的关联在人群中并不一致。在我们的研究中，在没有吸烟、大量饮酒和高血压的情况下，TC水平与癌症或全因死亡率增加无关。
