OBJECTIVETo investigate the impact of obesity and hypertension on the size of the left atrium.

METHODSA total of 383 subjects were divided into normal group (NS, n = 95), hypertension group (HT, n = 97), obesity group (OB, n = 98) and hypertension with obesity group (HT + OB, n = 93). Clinical information, echocardiographic parameters and left atrial size in the four groups were compared.

RESULTS(1) The left atrial volume index (LAVI) was arranged in the order: HT + OB > OB > HT > NS (28.07 ± 6.63 > 24.61 ± 4.89 > 22.73 ± 5.16 > 19.18 ± 4.82 ml/m, P < 0.05); Difference on LAVI was significant in four groups after adjusting for age, gender, HR, FPG, TC, TG and HDL (P < 0.05). (2) Pearson correlation analysis showed closer correlation between BMI with LAVI compared to SBP and DBP with LAVI (r values: 0.505, 0.240, 0.209, P < 0.001). After adjusting for other factors, the correlation between BMI and LAVI remains significant (β = 0.411, P < 0.001) while no significant relationship between SBP, DBP and LAVI was found. One unit BMI increase is associated with 0.052 cm enlargement of left atrial diameter (LAD), 1.053 ml increase of left atrial volume (LAV) and 0.710 ml/m increase of LAVI.

CONCLUSIONThe impact of obesity on the size of left atrium is greater than that of hypertension. Obesity and hypertension have synergistic effects on enlarging left atria.