Diabetes Care：糖尿病患者强化血压控制增加冠心病风险

在糖尿病患者中，控制血压可以降低冠心病（CHD）的风险；然而，最低冠心病风险的糖尿病患者是否伴随最低的血压水平仍不清除。为此，来自美国路易斯安那州彭宁顿生物医学研究中心的Gang Hu教授及其团队进行了一项研究，该研究发现血压与CHD风险之间呈U字形相关或负相关，但是，在伴有糖尿病的非裔美籍和白种人患者中间，强化血压控制（血压＜120/70mmHg）与CHD风险增加有关。该研究结果在线发表在2013年5月20日的《糖尿病治疗》（Diabetes Care）杂志上。

该研究是一项关于糖尿病患者的前瞻性队列研究，包括17536例非裔美国人和12618例白种人，使用COX比例风险回归模型评估血压与CHD风险的相关性。

该研究结果表明，在平均随访6年期间，发现了7260例CHD病例。基线不同收缩压/舒张压水平（＜110/65、110–119/65–69、120–129/70–80、以及130–139/80–90mmHg[参照组]、140–159/90–100、和≥160/100mmHg）相关的CHD多元校正风险比在非裔美籍糖尿病患者分别为7.73、1.16、1.04、1.00、1.06、以及1.11（P＜0.001），在白种人糖尿病患者分别为1.60、1.27、1.08、1.00、0.95、以及0.99（P＜0.001）。在非裔美籍和白种人糖尿病患者在随访期间，观察到基线单独的收缩压和舒张压与血压一样，与CHD风险乘U字形相关（P＜0.001）。在青年组（30-49岁）呈现U字形相关，但在老年组（≥60岁），这个U字形相关变更为负相关。

该研究发现，血压与CHD风险之间呈U字形相关或负相关，但是，在伴有糖尿病的非裔美籍和白种人患者中间，强化血压控制（血压＜120/70mmHg）与CHD风险增加有关。

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.