PS-C27-2: RISK OF PSEUDO-MICROALBUMINURIA DURING MENSTRUAL SITUATION IN APPARENTLY HEALTHY WORKERS

Abstract

Background: Measurement of urinary albumin excretion (UAE) is useful for the prediction of future cardiovascular event and is now used not only in clinical but also in health-check up or industrial settings. Especially, microalbuminuria (MA) is an important category of early vascular marker to alert lifestyle modification and/or pharmacological treatment. In the working female population, however, examination of urine in above settings could encounter menstrual situation. Contamination of menstrual blood into urine could induce pseudo-microalbuminuria. However, it has never been studied in apparently healthy women how much of contamination of menstrual blood could increase the risk of pseudo-microalbuminuria. To address this issue, we examined the relationship between urine occult blood level and UAE or frequency of MA cases during menstrual and non-menstrual situation in apparently healthy workers. Subjects and method: We studied 735 female school workers who participated in the Miyagi Karoshi Prevention study. Urinary albumin excretion adjusted for creatinine (UAE) from morning spot urine sample was examined together with annual health check-up in 2019 and 2020. Menstrual situation was confirmed by a questionnaire at the time of examination. One hundred and forty-four non-diabetic, non-hypertensive women without chronic kidney disease (36.9 ± 9.2yrs) were studied either during menstrual or non-menstrual situation in the 2 consecutive years. We compared clinical data during menstrual and non-menstrual situation and then examined the dose-response relationship between urine occult blood category (negative to three plus) and UAE or frequency of MA cases at menstrual and non-menstrual situation. Results: Menstrual situation was associated with significantly higher UAE (4.6 vs. 3.4 mg/gCr, p < 0.001), systolic BP (113.6 ± 13.1 vs. 111.3 ± 12mmHg, p = 0.015) and uric acid level (4.3 ± 0.8 vs. 4.10.9 ± mg/dl, p = 0.004) and was associated with significantly lower high density lipoprotein cholesterol (70.0 ± 14.4 vs. 72.7 ± 16.3 mg/dl, p < 0.001) and eGFR(85.0 ± 14.6 vs, 87.7 ± 16.9 ml/min/1.73m2, p = 0.003) as compared with non-menstrual situation. In menstrual situation, UAE was dose-dependently increased with an increase in urine occult blood category (p < 0.001). Frequency of MA in each urine blood category was 0, 0, 4.5, 0 and 17% (p = 0.001), respectively. UAE was not correlated with systolic BP or other parameters during menstrual situation. In non-menstrual situation, there was no correlation with UAE and urine occult blood level. Conclusion: Risk of pseudo-microalbuminuria could abruptly rise if urine occult blood level reach three plus in menstruated women.