Objective

To investigate the relevant factors of coronary artery disease (CAD) in young people under 40 years of age.

Methods

The study population was 292 young patients accepting coronary angiography in Fuwai Hospital from July to December 2006

including 272 men and 20 women

with the mean age being 36.7±3.7 years. The diagnosis of CAD was made in the cases presenting ≥50% stenosis in coronary lumen in coronary angiography. Based on the diagnosis

217 patients (204 men

13 women) were assigned to CAD group

and 75 (68 men

7 women) to non-CAD group. Clinical data and metabolic characteristics of the patients were collected and analyzed using t-test

χ

2

test

and multinomial logistic regression with SPSS 8.0 software.

Results

Most study subjects were current smokers (209/292

71.6%)

and more than half had body mass index (BMI)

>

24 kg/m

2

(230/292

78.8%) and usually took high-fat diet (162/292

55.5%). The proportion of heavy smokers (smoking history ≥10 years and ≥20 cigarettes per day) were significantly higher in the CAD group than in the non-CAD group [20.7% (45/217) vs. 9.3% (7/75)

P=0.015)]. Heavy smoking [odds ratio (OR)

1.89; 95% confidence interval (CI)

1.74-2.05]

hypertension (OR

1.56; 95% CI

1.48-1.65)

alcohol (OR

1.37; 95% CI

1.30-1.46)

type 2 diabetes mellitus (OR

1.37; 95% CI

1.25-1.50)

high-fat diet (OR

1.35; 95% CI

1.28-1.43)

and BMI

>

24 kg/m

2

(OR

1.09; 95% CI

1.03-1.17) were factors related to CAD in the young patients (all P

<

0.05). Total cholesterol (4.56±1.46 mmol/L vs. 4.09±1.00 mmol/L)

low-density lipoprotein cholesterol (2.38±1.11 mmol/L vs. 2.14±0.63 mmol/L)

lipoprotein a (134.97±109.70 mg/L vs. 101.58±58.39 mg/L)

uric acid (359.89±100.09 μmol/L vs. 336.75±94.36 μmol/L)

erythrocyte sedimentation rate (9.98±12.19 mm/hour vs. 4.89±4.92 mm/hour)

high-sensitivity C-reactive protein (3.42±4.39 mg/L vs. 2.80±3.77 mg/L) and Big endothelin-1 (1.41±1.50 fmol/mL vs. 0.77±1.13 fmol/mL) in plasma were significantly increased in the CAD group compared with the non-CAD group (all P

<

0.05).

Conclusions

Heavy smoking

hypertension

alcohol consumption

type 2 diabetes mellitus

high-fat diet and BMI

>

24 kg/m

2

were significantly related to CAD in patients aged ≤ 40

with heavy smoking presenting the highest OR. Metabolic syndrome and inflammation were also more common in young CAD patients than in non-CAD patients.