Letrozole increases preantral follicle growth and decreases estradiol production without impairing follicle survival.

BACKGROUND: Letrozole has been reported to be effective in treating anovulation, preventing ovarian hyperstimulation syndrome (OHSS), and retrieving oocytes in breast cancer patients. However, the role and mechanism of letrozole in follicular development remain unclear. RESULTS: We treated mouse preantral follicles with various treatments; we found no significant difference in follicle survival rates in the letrozole (LET) group compared with the control group, but the average diameter of follicles in the LET group tended to be larger (CTRL vs. LET 30, p = 0.064; CTRL vs. LET 100, p = 0.025). The estradiol concentrations in culture media of the LET group were significantly lower than those observed in the control group (CTRL vs. LET 30, p = 0.038; CTRL vs. LET 100, p = 0.025). We further found a marked increase in follicle-stimulating hormone receptor (FSHR) gene expression in response to letrozole treatment (CTRL vs. LET 30, p = 0.075; CTRL vs. LET 100, p = 0.034). This result suggested that increased FSHR expression promotes follicle development. Letrozole inhibited aromatase activity, but the effect was limited. Letrozole did not significantly reduce vascular endothelial growth factor (VEGF) gene expression. CONCLUSIONS: Letrozole may promote follicle development by increasing the expression of FSHR. Letrozole may be useful for fertility preservation of patients with estrogen-dependent cancers such as breast cancer and various other cancers. Whether letrozole has a direct effect in reducing OHSS requires further investigation.

The Beneficial Effect of Personalized Lifestyle Intervention in Chronic Kidney Disease Follow-Up Project for National Health Insurance Specific Health Checkup: A Five-Year Community-Based Cohort Study.

Background and Objectives: Mimasaka city is a relatively small city with a population of 28,381, and an aging rate (≥65 years old) of 38.9%, where only one nephrology clinic is available. Since 2013, the city has conducted its own unique lifestyle intervention for the participants of the National Health Insurance specific medical health checkup, aiming to prevent the progression of chronic kidney disease (CKD) severity. Materials and Methods: The persons in National Health Insurance specific medical health checkup (40−74 years old) conducted in Mimasaka city in 2013, with eGFR less than 50 mL/min/1.73 m² or 50−90 mL/min/1.73 m² with urine dipstick protein 1+ or more, were registered for the CKD follow-up project, as high-risk subjects for advanced renal dysfunction. Municipal workers directly visited the subjects' homes to provide individual health guidance and encourage medical consultation. We aimed to examine the effect of home-visit intervention on the changes of renal function and related factors until 2017. Results: The number of the high-risk subjects who continuously received the health checkup until 2017 was 63, and only 23 (36.5%) visited a medical institution in the first year. The eGFR decreased by only 0.4 mL/min/1.73 m²/year, and the subjects with urinary protein 1+ or higher decreased significantly from 20 (31.7%) to 9 (14.3%) (p = 0.034) in the high-risk subjects. The changes in eGFR and urinary protein was almost in the same fashion regardless of their medical institution visits. Next, we examined the effects of various factors on ΔeGFR, the changes of eGFR from 2013 to 2017, by multivariate linear regression analysis. The effects of medical institution visit were not significant, and the degree of urinary protein (coefficient B: 4.503, ß: 0.705, p < 0.001), age (coefficient B: 4.753, ß: 0.341, p = 0.004), and smoking (coefficient B: 5.878, ß: 0.295, p = 0.031) had independent significant effects, indicating that they were the factors exacerbating the decrease in eGFR from the baseline. Conclusions: The personalized lifestyle intervention by home-visit in CKD follow-up project showed the possibility of beneficial effects on the deterioration of renal function. This may be an efficient method to change behavior in a small community with limited medical resources.