Characteristics of the study participants are presented in . Mean disease duration was 16 years in both groups. The women with SLE were younger than those with RA, more likely to be premenopausal, and more likely to be taking HCQ than those with RA. Of the women taking HCQ, the mean daily dose for those with SLE was 336 ± 98 mg, and for those with RA, it was 213 ± 50 mg (p < 0.0001).
Patient characteristics (mean ± SD unless otherwise noted).
For women with SLE, those taking HCQ had lower fasting glucose, HOMA-IR, and low-density lipoprotein (LDL) levels, and were more likely to report current daily prednisone use than those not taking HCQ (). For women with RA, those taking HCQ had higher HOMA-B and lower atherogenic ratio, and were less likely to be taking nonbiologic DMARD than those not taking HCQ.
In the multivariable models for women with SLE (), HCQ users had a significantly lower fasting glucose than the nonusers (85.9 vs 89.3 mg/dl, p = 0.04). In post-menopausal women, current use of hormone replacement therapy did not alter the effect of HCQ on fasting glucose levels (85.8 vs 91.2 mg/dl, p = 0.01); but hormone replacement therapy was associated with lower glucose in bivariate analyses (84.2 ± 8.4 vs 91.4 ± 10.6 mg/dl, p = 0.02). Exploratory analyses of a dose-response relationship between glucose and HCQ usage [comparing none, low (100–250 mg), and high (400 mg) doses of HCQ] were not significant. Back-transforming results of the adjusted means, for ease of clinical interpretation, suggested that HOMA-IR was lower in the HCQ users than nonusers (2.64 vs 3.06, p = 0.09). Stratified analyses ( and ) suggest that the association between HCQ and lower fasting glucose and higher HOMA-B was present in prednisone nonusers, while the association between lower HOMA-IR was more evident among prednisone users.
Table 3 Comparison of glucose metabolism by HCQ and disease status, by mean value adjusted for age, disease duration, waist circumference, prednisone dose, CRP, menopausal status, and NSAID; plus (a) immuno-suppressants and SLEDAI for women with SLE, or (b) nonbiologic (more ...)
Table 4A Comparison of glucose metabolism by HCQ and disease status among women not using prednisone, by mean value adjusted for age, disease duration, waist circumference, predrisone dose, CRP, menopausal status, and NSAID; plus (a) immunosuppressants and SLEDAI (more ...)
Table 4B Comparison of glucose metabolism by HCQ and disease status among prednisone users, by mean value adjusted for age, disease duration, waist circumference, prednisone dose, CRP, menopausal status, and NSAID; plus (a) immunosuppressants and SLEDAI for women (more ...)
In the multivariable models for women with RA (), HCQ users also had a significantly lower fasting glucose than the nonusers (82.5 vs 86.6 mg/dl, p = 0.051). The lower fasting glucose levels for women taking HCQ were more evident in postmenopausal women with RA (85.8 vs 91.2 mg/dl, p = 0.01), with no association between hormone replacement therapy and glucose in bivariate analyses (88.8 ± 10.3 vs 88.4 ± 10.3 mg/dl, p = 0.86). No differences in logHOMA-IR or loginsulin by HCQ usage were seen in women with RA. Back-transforming results of the adjusted means suggested that HOMA-B was higher in the HCQ users than nonusers (235 vs 181, p = 0.09). Exploratory analyses showed a trend for an interaction between HCQ use and prednisone use (any/none) in multivariable models for glucose (p = 0.02), loginsulin (p = 0.04), logHOMA-IR (p = 0.15), and logHOMA-B (p = 0.002). Stratified analyses suggested that lower glucose may be most evident among prednisone users, while lower insulin and higher HOMA-B levels may be most evident in women not taking prednisone ( and ).