Hyporetinolemia, illness symptoms, and acute phase protein response in pregnant women with and without night blindness

Abstract

We examined the association among elevations in acute phase proteins, reported illness, and hyporetinolemia in 234 pregnant Nepali women with (cases) and without (controls) night blindness. Serum α1-acid glycoprotein (AGP) and C-reactive protein (CRP) were inversely associated with serum retinol concentrations. Elevations in the concentration of CRP in both cases and controls and of AGP in cases were associated with significant reductions (≃0.2-0.3 μmol/L) in serum retinol. The risk of a low serum retinol concentration (< 0.7 μmol/L) with elevated AGP (≤ 1 g/L) and CRP (≤ 5 mg/L) concentrations was significantly higher in cases (odds ratios = 8.6 and 4.3, respectively) than in controls (odd ratios = 1.9 and 2.4, respectively). A 7-d morbidity history indicated that cases were significantly more likely than controls to report symptoms of infections of the urinary, reproductive, and gastrointestinal tracts. Only a few of these symptoms (diarrhea, nausea, and vomiting) were significantly associated with low serum retinol concentrations. Illness in the previous week and elevated CRP or AGP concentrations were synergistically associated with lower serum retinol. For example, the reduction in serum retinol in women with diarrhea and elevated AGP was 0.54 μmol/L, compared with a reduction of 0.03 μmol/L in those with diarrhea only. AGP and CRP may provide useful information about the effect of reported illness on hyporetinolemia in pregnancy. Infection-related hyporetinolemia may predispose women to night blindness during pregnancy in Nepal.