胸腹鈣化可能預測心血管死亡率
作者：Laurie Barclay, MD
出處：WebMD醫學新聞
January 8, 2010 — 根據一項線上發表於2009年12月15日糖尿病照護（Diabetes Care）期刊的研究結果，放射線攝影上胸腹鈣化可以預測心血管與整體死亡率。
芬蘭庫皮歐大學醫院的Auni Juutilainen醫師與其同事們寫到，血管因代謝、機械或是發炎傷害引發血管鈣化。這個疾病進程主要由血管損傷的發炎反應決定。對於第二型糖尿病患者以及一般大眾來說，這可能發生在心血管疾病（CVD）發病或死亡數年、甚至數十年前。
這項研究的目的在於決定放射線攝影上胸腹鈣化對於CVD與整體死亡率的影響。這個試驗族群收納833位第二型糖尿病患者，和1,292位沒有糖尿病的受試者，這些受試者接受後續追蹤長達18年，他們的年齡範圍從45~64歲，且在試驗前沒有罹患CVD證據。研究者在校正傳統危險因子後計算危險比值（HRs）。
顯著胸腹鈣化與CVD及整體死亡率有關。罹患第二型糖尿病男性，CVD死亡率HR為1.5（95%信賴區間[CI]為0.8-3.0）、整體死亡率HR為1.8（95% CI為1.1-2.9），第二型糖尿病女性CVD死亡率HR為3.0（95% CI為1.6-5.7）、整體死亡率HR為3.1（95% CI為1.9-5.0）；非糖尿病男性CVD死亡率HR為5.0（95% CI為2.2-12）、整體死亡率HR為4.0（95% CI為2.2-7.4），非糖尿病女性CVD死亡率HR為7.8（95% CI為1.8-34）、整體死亡率HR為3.0（95% CI為1.3-7.0）。
高敏感度C反應蛋白（hs-CRP）存在改變HR值。Hs-CRP濃度低於3 mg/L，第二型糖尿病受試者HR為2.4（95% CI為1.3-4.4）；濃度低於3 mg/L為3.0（95% CI為1.4-6.1）。在沒有糖尿病的患者中，hs-CRP低於3 mg/L的HR為4.0（95% CI為1.5-10.8），高於3 mg/L的為6.6（95% CI為2.7-16.0）。
研究作者們寫到，原生放射線攝影上的胸腹鈣化是CVD與整體死亡率的顯著預測因子，特別是第二型糖尿病與hs-CRP濃度過高的非糖尿病女性。
這項研究的限制包括因為遺失數據排除了部分受試者。
研究作者們的結論是，結合hs-CRP，這是個粥狀動脈硬化活性的代理標記，再加上出現鈣化，這是粥狀動脈硬化分級的代理標記，增加了預後上的價值。根據目前的這項研究結果，偵測到胸腹放射線攝影鈣化應該進一步評估和治療CVD風險。
Thoracoabdominal Calcifications May Predict Cardiovascular Mortality
By Laurie Barclay, MD
Medscape Medical News
January 8, 2010 — Thoracoabdominal calcifications on radiography predict cardiovascular and total mortality, according to the results of an 18-year follow-up study reported online in the December 15, 2009, issue of Diabetes Care.
"Vascular calcification is initiated by metabolic, mechanical, infectious, or inflammatory injury to vasculature," write Auni Juutilainen, MD, from Kuopio University Hospital in Kuopio, Finland, and colleagues. "Its progression is mainly determined by inflammatory response to vascular injury. It may precede cardiovascular disease (CVD) morbidity and mortality by years or decades in subjects with type 2 diabetes and in [the] general population."
The goal of this study was to determine CVD and total mortality associated with thoracoabdominal calcifications on radiography. The study cohort consisted of 833 participants with type 2 diabetes and 1292 participants without evidence of diabetes who were followed up for 18 years. Age range was 45 to 64 years, and participants had no evidence of CVD at baseline. Hazard ratios (HRs) were adjusted for conventional risk factors.
Marked thoracoabdominal calcifications were associated with CVD and total mortality. In type 2 diabetic men, HRs were 1.5 for CVD mortality (95% confidence interval [CI], 0.8 - 3.0) and 1.8 for total mortality (95% CI, 1.1 - 2.9). HRs were 3.0 for CVD mortality (95% CI, 1.6 - 5.7) and 3.1 for total mortality (95% CI, 1.9 - 5.0) in type 2 diabetic women, 5.0 for CVD mortality (95% CI, 2.2 - 12) and 4.0 for total mortality (95% CI, 2.2 - 7.4) in nondiabetic men, and 7.8 for CVD mortality (95% CI, 1.8 - 34) and 3.0 for total mortality (95% CI, 1.3 - 7.0) in nondiabetic women.
The presence of high-sensitivity C-reactive protein (hs-CRP) modified the HR. For hs-CRP levels less than 3 mg/L, the HR in type 2 diabetic subjects was 2.4 (95% CI, 1.3 - 4.4); for levels more than 3 mg/L, it was 3.0 (95% CI, 1.4 - 6.1). In nondiabetic subjects, the HR was 4.0 for hs-CRP levels less than 3?mg/L (95% CI, 1.5 - 10.8) and 6.6 for levels more than 3 mg/L (95% CI, 2.7 - 16.0).
"Thoracoabdominal calcifications in native radiograms are significant predictors of CVD and total mortality especially in type 2 diabetic and non-diabetic women with elevated hs-CRP level," the study authors write.
Limitations of this study include exclusion of some subjects because of missing data points.
"Combining hs-CRP — a surrogate of activity of atherosclerosis — with the presence of calcifications — a surrogate of stage of atherosclerosis — the prognostic value improves," the study authors conclude. "Based on the findings of the present study, detection of thoracoabdominal radiological calcification should lead to a detailed evaluation and treatment of CVD risk."
Diabetes Care. Published online December 15, 2009.
