[Analysis of muscle strength and body composition of women with polycystic ovary syndrome].

PURPOSE

To compare the metabolic parameters, body composition and muscle strength of women with Polycystic Ovary Syndrome (PCOS) to those of women with ovulatory menstrual cycles.

METHODS

A case-control study was conducted on 27 women with PCOS and 28 control women with ovulatory cycles, aged 18 to 27 years with a body mass index of 18 to 39.9 kg/m², who did not practice regular physical activity. Serum testosterone, androstenedione, prolactin, sex hormone-binding globulin (SHBG), insulin and glycemia levels were determined. Free androgen index (FAI) and resistance to insulin (by HOMA) were calculated. The volunteers were submitted to evaluation of body composition based on skin folds and DEXA and to 1-RM maximum muscle strength tests in three exercises after familiarization procedures and handgrip isometric force was determined.

RESULTS

Testosterone levels were higher in the PCOS group than in the Control Group (68.07 ± 20.18 versus 58.20 ± 12.82 ng/dL; p=0.02), as also were the FAI (282.51 ± 223.86 versus 127.08 ± 77.19; p=0.01), insulin (8.41 ± 7.06 versus 4.05 ± 2.73 µIU/mL; p=0.01), and HOMA (2.3 ± 2.32 versus 1.06 ± 0.79; p=0.01), and SBHG levels were lower (52.51 ± 43.27 versus 65.45 ± 27.43 nmol/L; p=0.04). No significant differences in body composition were observed between groups using the proposed methods. The PCOS group showed greater muscle strength in the 1-RM test in the bench press (31.2 ± 4.75 versus 27.79 ± 3.63 kg; p=0.02), and leg extension exercises (27.9 ± 6.23 versus 23.47 ± 4.21 kg; p=0.02) as well as handgrip isometric force (5079.61 ± 1035.77 versus 4477.38 ± 69.66 kgf/m², p=0.04). PCOS was an independent predictor of increase muscle strength in bench press exercises (estimate (E)=2.7) (p=0.04) and leg extension (E=3.5) (p=0.04), and BMI in the exercise of isometric handgrip (E=72.2) (p<0.01), bench press (E=0.2) (p=0.02) and arm curl (E=0.3) (p<0.01). No association was found between HOMA-IR and muscle strength.

CONCLUSIONS

Women with POS showed greater muscle strength, with no difference in body composition, and IR was not associated with muscle strength performance. Muscle strength may be possibly related to high levels of androgens in these women.