Transitions in Blood Hemoglobin Levels and Platelet Counts in 32–65-year-old Female Examinees Undergoing Periodic Health Check-ups

Abstract

Objective: Cross-sectional surveys have shown blood hemoglobin (Hb) levels to be low in women in their 30s and 40s. This study investigated secular transitions in blood Hb levels and relevant laboratory data in women aged in their 30s to mid-60s.

Methods: We included the data of 1,370 women who underwent at least six periodic health check-ups, including those for blood Hb level, mean corpuscular volume (MCV), and platelet count. The transitions in and mutual relationships of these data were investigated.

Results: In women who did not receive anemia treatment at any health check-up, blood Hb levels began to decrease when they were in their mid-30s, remained low during their 40s, and increased again in their 50s. This tendency was stronger in women with anemia history than in those without anemia history. MCV decreased and platelet count increased in women in their 40s, but returned to previous levels in their 50s. The average age of menopause during the study period was 50.9 ± 3.1 (SD) years. Platelet count exceeded the reference value in 17.1% of women with blood Hb levels≤ 11.0 g/dL. A strong negative correlation was observed between individual blood Hb level and platelet count over time, especially with blood Hb level fluctuations ≥ 3 g/dL.

Conclusions: The blood Hb level of women decreased when the women were in their 40s and recovered during their 50s. These changes were small in those without previous anemia history. As the blood Hb level decreased, the proportion of women with platelet counts exceeding the reference value slightly increased.