Public Health Agency of Canada, 200, boulevard René-Lévesque Ouest, Montréal, QC H2Z 1X4, Canada.
Popul Health Metr. 2013 Nov 19;11(1):21. doi: 10.1186/1478-7954-11-21.
While many studies have examined differences between body mass index (BMI) categories in terms of mortality risk and health-related quality of life (HRQL), little is known about the effect of body weight on health expectancy. We examined life expectancy (LE), health-adjusted life expectancy (HALE), and proportion of LE spent in nonoptimal (or poor) health by BMI category for the Canadian adult population (age ≥ 20).
Respondents to the National Population Health Survey (NPHS) were followed for mortality outcomes from 1994 to 2009. Our study population at baseline (n=12,478) was 20 to 100 years old with an average age of 47. LE was produced by building abridged life tables by sex and BMI category using data from the NPHS and the Canadian Chronic Disease Surveillance System. HALE was estimated using the Health Utilities Index from the Canadian Community Health Survey as a measure of HRQL. The contribution of HRQL to loss of healthy life years for each BMI category was also assessed using two methods: by calculating differences between LE and HALE proportional to LE and by using a decomposition technique to separate out mortality and HRQL contributions to loss of HALE.
At age 20, for both sexes, LE is significantly lower in the underweight and obesity class 2+ categories, but significantly higher in the overweight category when compared to normal weight (obesity class 1 was nonsignificant). HALE at age 20 follows these same associations and is significantly lower for class 1 obesity in women. Proportion of life spent in nonoptimal health and decomposition of HALE demonstrate progressively higher losses of healthy life associated with lowered HRQL for BMI categories in excess of normal weight.
Although being in the overweight category for adults may be associated with a gain in life expectancy as compared to normal weight adults, overweight individuals also experience a higher proportion of these years of life in poorer health. Due to the descriptive nature of this study, further research is needed to explore the causal mechanisms which explain these results, including the important differences we observed between sexes and within obesity subcategories.
虽然许多研究已经检查了身体质量指数 (BMI) 类别在死亡率风险和健康相关生活质量 (HRQL) 方面的差异，但对于体重对健康预期寿命的影响知之甚少。我们检查了加拿大成年人口（年龄≥20 岁）的预期寿命 (LE)、健康调整后的预期寿命 (HALE) 和非最佳 (或较差) 健康状态的 LE 比例，按 BMI 类别进行划分。
从 1994 年到 2009 年，对国家人口健康调查 (NPHS) 的受访者进行了死亡率结果的随访。我们的基线研究人群（n=12478）年龄在 20 至 100 岁之间，平均年龄为 47 岁。通过使用 NPHS 和加拿大慢性疾病监测系统的数据，为男性和 BMI 类别构建简化生命表来生成 LE。使用加拿大社区健康调查的健康效用指数作为 HRQL 的衡量标准来估计 HALE。还使用两种方法评估每个 BMI 类别中 HRQL 对健康生命年损失的贡献：通过计算 LE 和 HALE 之间与 LE 成比例的差异，以及使用分解技术将死亡率和 HRQL 对 HALE 损失的贡献分开。
在 20 岁时，对于两性，与正常体重相比，体重不足和肥胖 2+类别的 LE 显著降低，但超重类别的 LE 显著升高（肥胖 1 类无显著差异）。20 岁时的 HALE 遵循相同的关联，女性肥胖 1 类的 HALE 显著降低。非最佳健康状态的比例和 HALE 的分解表明，与正常体重成年人相比，BMI 类别超过正常体重与较低的 HRQL 相关，健康生命年的损失更高。
虽然与正常体重成年人相比，成年人处于超重类别可能与预期寿命的增加有关，但超重人群也经历了更高比例的这些生命年处于较差的健康状态。由于本研究的描述性性质，需要进一步研究来探索解释这些结果的因果机制，包括我们在性别和肥胖亚类别内观察到的重要差异。
