Diabetes Care：老年患者血压和冠心病风险呈负相关

　　美国一项研究表明，血压和冠心病风险之间存在U型相关或负相关，激进的血压控制（aggressive blood pressure control ，<120/70 mmHg）与冠心病风险升高具有相关性。论文5月20日在线发表于《糖尿病护理》（Diabetes Care）。

　　此项前瞻性队列研究共纳入17536例非洲裔美国人和12618例白人糖尿病患者。利用Cox比例风险回归模型评估血压与冠心病风险的相关性。

　　结果显示，在平均6.0年随访期间共确认7260例冠心病偶发病例。在非洲裔美国人糖尿病患者中，与不同基线收缩/舒张压水平[<110/65、110～119/65～69、120～129/70～80和130～139/80～90 mmHg（参照组）；140–159/90–100和≥160/100 mmHg]相关的冠心病多变量校正危险比分别为1.73、1.16、1.04、1.00、1.06和1.11；在白人糖尿病患者则分别为1.60、1.27、1.08、1.00、0.95和0.99。在两组人群中均可观察到基线时孤立收缩和舒张压以及随访期间血压与冠心病风险的U型相关。在较为年轻的人群中(30～49岁)中存在上述U型相关，在老年人群中（≥60岁）则转换为负相关。

Aggressive Blood Pressure Control Increases Coronary Heart Disease Risk Among Diabetic Patients
OBJECTIVE
Blood pressure control can reduce the risk of coronary heart disease (CHD) among diabetic patients; however, it is not known whether the lowest risk of CHD is among diabetic patients with the lowest blood pressure level.
RESEARCH DESIGN AND METHODS
We performed a prospective cohort study (2000–2009) on diabetic patients including 17,536 African American and 12,618 white. Cox proportional hazards regression models were used to estimate the association of blood pressure with CHD risk.
RESULTS
During a mean follow-up of 6.0 years, 7,260 CHD incident cases were identified. The multivariable-adjusted hazard ratios of CHD associated with different levels of systolic/diastolic blood pressure at baseline (<110/65, 110–119/65–69, 120–129/70–80, and 130–139/80–90 mmHg [reference group]; 140–159/90–100; and ≥160/100 mmHg) were 1.73, 1.16, 1.04, 1.00, 1.06, and 1.11 (P trend <0.001), respectively, for African American diabetic patients, and 1.60, 1.27, 1.08, 1.00, 0.95, and 0.99 (P trend<0.001) for white diabetic patients, respectively. A U-shaped association of isolated systolic and diastolic blood pressure at baseline as well as blood pressure during follow-up with CHD risk was observed among both African American and white diabetic patients (all P trend <0.001). The U-shaped association was present in the younger age-group (30–49 years), and this U-shaped association changed to an inverse association in the older age-group (≥60 years).
CONCLUSIONS
Our study suggests that there is a U-shaped or inverse association between blood pressure and the risk of CHD, and aggressive blood pressure control (blood pressure <120/70 mmHg) is associated with an increased risk of CHD among both African American and white patients with diabetes.