Background/Purpose: Excessive body mass among healthy subjects carries an increased risk of subsequent cardiovascular (CV) events.  In healthy subjects, the relationship between body mass index (BMI) and total and CV mortality follows a U-shaped curve, with the lowest mortality in overweight (BMI 25.0−29.9 kg/m²) and mildly obese (BMI 30.0−34.9 kg/m²) individuals. Despite a high burden of CV disease in systemic lupus erythematosus (SLE), the relationship between BMI and CV outcomes in SLE has not been studied.

Methods: We estimated the effect of BMI on CV events in a cohort of 2000 patients with SLE. We analyzed the rate of CV events during cohort participation, for five predetermined body weight groups: low (BMI<20 kg/m²), normal weight (reference, BMI 20-24.9 kg/m²), overweight (25-29.9 kg/m²), obese (BMI 30-34.9 kg/m²), and severely obese (BMI>35 kg/m²).  CV events were defined as either stroke, myocardial infarction, incident angina, a coronary procedure (CABG or PCI), or claudication.  Those with a CV event prior to cohort entry were excluded. We adjusted for various confounding factors (age, sex, race, complement, hematocrit, anti-dsDNA, immunosuppressant use), including related CV risk factors: hypertension, hypercholesterolemia, diabetes and smoking.

Results: There were 140 CV events observed over 11,374 person-years of follow-up. The rate of CV events per 1000 patient years of follow up was 6.0 for low weight,  9.3 for normal weight, 14.5 for overweight, 17 for obese, and 13.2 for severely obese. The rate of CV events in obese patients was statistically significantly higher compared to patients with normal weight (p=0.015) in a non adjusted model. After adjusting for confounding factors the p-value approached statistical significance (p=0.062).           

BMI (kg/m2)	Person-years	CV events	Rate1	Unadjusted model		Adjusted model
				RR (95% CI)	P-value	RR (95% CI)	P-value
<20	1006	6	6.0	0.6 (0.3, 1.5)	0.31	0.5 (0.2, 1.3)	0.14
20-24.9	3644	34	9.3	1.0 (REF.GP)		1.0 (Ref. Gp)
25-29.9	3095	45	14.5	1.6 (1.0, 2.4)	0.051	1.2 (0.7, 1.9)	0.52
30-34.9	1884	32	17.0	1.8 (1.1, 3.0)	0.015	1.6 (0.9, 2.7)	0.078
>35	1744	23	13.2	1.4 (0.8, 2.4)	0.20	1.1 (0.6, 2.0)	0.73
1 Per 1000 person years

Conclusion: Obesity (BMI 30-34.9 kg/m²) is associated with the highest rate of adverse cardiovascular events in SLE. Interestingly, the CV event rate in severe obesity (BMI>35 kg/m²) was lower than in overweight and obese patients, suggesting the presence of a unique obesity paradox in SLE that differs from the one described in the general population.

---

« Back to 2012 ACR/ARHP Annual Meeting

ACR Meeting Abstracts - https://acrabstracts.org/abstract/association-of-body-weight-with-cardiovascular-events-in-systemic-lupus-erythematosus/