Auteurs : Christophe MULUMBA1, Gabriel LUKUSA2, Gorby NDAIE1, Pierrot LEBUGHE1, Aldo MAVINGA1, Jenny
MBUYI 1, Jean-Marie Mbuyi MUAMBA1

1Rheumatology Service, Department of internal medicine, University hospitals of Kinshasa, Democratic Republic of the
Congo. 2 Clinical Biology Service, Department of Medical Biology, University Hospital of Kinshasa, Democratic
Republic of the Congo.

ABSTRACT

Background: Rheumatoid arthritis (RA) is often associated with an increased atherogenic index, which raises the cardiovascular risk. This study aimed, first, to compare the atherogenic index between patients with RA and osteoarthritic controls and, second, to identify the factors associated with its elevation among patients with RA
followed in our setting. Methods: This case–control study was conducted between January 2015 and December 2021 and included 122 patients with RA and 244 age- and sex-matched controls, who were consecutively recruited. The control group consisted of adult patients followed for osteoarthritis, recruited from the same hospital facilities during the same period, and with no history of chronic inflammatory rheumatic disease. Clinical examination was performed to assess cardiovascular risk factors. Laboratory investigations included lipid profile, fasting blood glucose, serum uric acid, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and
rheumatoid factor. The atherogenic index was calculated as TC/HDLc and considered elevated when > 4.85, or as LDL/HDL when > 3.55.
Logistic regression analysis was performed to identify factors associated with an elevated atherogenic index. Statistical significance was defined as a p-value < 0.05. Results: One in two RA patients (54.1%) had an elevated atherogenic index, compared with 20.5% of controls. RA patients with an elevated atherogenic index had an
inflammatory syndrome that was almost three times more pronounced than in controls for ESR: 35.5 (28.0-70.0) mm/h1 versus 12.5 (9.0-14) mm/h1 and almost five times more pronounced for CRP: 18.0 (7.8-36.0) mg/l versus 3.9 (3.0-4.9) mg/l, with a highly significant difference. They also had hypertriglyceridemia (157.0±47.2 mg/dl
versus 135.5±48.9 mg/dl). The controls had an increased pulse pressure (59.3±17.2 mm Hg versus 51.7±15.1 mm Hg), an increased waist circumference (100.6±14.2 cm versus 90.6±11.1 cm), an increased BMI (29.6±5.6 kg/m2 versus 24.6±5.0 kg/m2) and an increased uric acid level (5.7(4.9-6.5) mg/dl versus 4.9(4.0-5.7) mg/dl).
This increased atherogenic index was not correlated with disease duration, disease activity, or corticosteroid use. In multivariable analysis, menopausal duration greater than 10 years (p = 0.008; aOR = 2.62, 95% CI: 1.29–5.32), metabolic syndrome (p < 0.001; aOR = 6.18, 95% CI: 3.17–8.05), and abdominal obesity (p = 0.004; aOR = 2.61, 95% CI: 1.35–5.04) were independently associated with an elevated atherogenic index. Conclusion: Elevated atherogenic index was significantly more common in RA patients than in controls. Its independent determinants were menopausal duration greater than 10 years, metabolic syndrome, and abdominal obesity. These findings underscore the need for systematic cardiometabolic assessment in rheumatoid arthritis to improve cardiovascular risk prevention.
Key words: Atherogenic index; Rheumatoid arthritis; Kinshasa; Democratic Republic of the Congo.

Afri J Rheum, Vol. 14, No. 1, 2026

https://ajrheuma.org