Tseng Chin-Lin, Brimacombe Michael, Xie Minge, Rajan Mangala, Wang Hongwei, Kolassa John, Crystal Stephen, Chen Ting-Cheng, Pogach Leonard, Safford Monika
Center for Health Care Knowledge Management, Department of Veterans Affairs New Jersey Health Care System, 385 Tremont Avenue #129, East Orange, NJ 07018, USA.
Am J Epidemiol. 2005 Mar 15;161(6):565-74. doi: 10.1093/aje/kwi071.
The purpose of this study was to investigate seasonal variations in population monthly hemoglobin A(1c) (A1c) values over 2 years (from October 1998 to September 2000) among US diabetic veterans. The study cohort included 285,705 veterans with 856,181 A1c tests. The authors calculated the monthly average A1c values for the overall population and for subpopulations defined by age, sex, race, insulin use, and climate regions. A1c values were higher in winter and lower in summer with a difference of 0.22. The proportion of A1c values greater than 9.0% followed a similar seasonal pattern that varied from 17.3% to 25.3%. Seasonal autoregressive models including trigonometric function terms were fit to the monthly average A1c values. There were significant seasonal effects; the seasonal variation was consistent across different subpopulations. Regions with colder winter temperatures had larger winter-summer contrasts than did those with warmer winter temperatures. The seasonal patterns followed trends similar to those of many physiologic markers, cardiovascular and other diabetes outcomes, and mortality. These findings have implications for health-care service research in quality-of-care assessment, epidemiologic studies investigating population trends and risk factors, and clinical trials or program evaluations of treatments or interventions.
本研究的目的是调查1998年10月至2000年9月这两年间美国糖尿病退伍军人人群每月糖化血红蛋白A1c（A1c）值的季节性变化。研究队列包括285,705名退伍军人，共进行了856,181次A1c检测。作者计算了总体人群以及按年龄、性别、种族、胰岛素使用情况和气候区域定义的亚人群的每月平均A1c值。A1c值冬季较高，夏季较低，差值为0.22。A1c值大于9.0%的比例呈现类似的季节性模式，在17.3%至25.3%之间变化。将包含三角函数项的季节性自回归模型应用于每月平均A1c值。存在显著的季节效应；不同亚人群的季节性变化是一致的。冬季温度较低的地区，冬夏差异比冬季温度较高的地区更大。季节性模式与许多生理指标、心血管及其他糖尿病结局以及死亡率的趋势相似。这些发现对医疗服务研究在医疗质量评估、调查人群趋势和风险因素的流行病学研究以及治疗或干预措施的临床试验或项目评估方面具有启示意义。
