Effect of Excess Weight on Health Related Quality of Life of Women with Polycystic Ovary Syndrome: An Age- and BMI-matched Case Control Study
Although the physical aspects of the health-related quality of life (HRQOL) are adversely affected by overweight in both Polycystic Ovarian Syndrome (PCOS) and control, but these impaired effects are greater in women with PCOS.
Polycystic Ovarian Syndrome (PCOS) is one of the most common endocrinopathies in women of reproductive age, with incidences ranging between 4–20%. It is characterized by menstrual and ovulatory dysfunction, infertility, hirsutism and increased cardiovascular risk factors. All these factors can negatively affect the health-related quality of life (HRQOL).
Polycystic Ovarian Syndrome (PCOS) is one of the most common endocrinopathies in women of reproductive age, with incidences ranging between 4–20%. It is characterized by menstrual and ovulatory dysfunction, infertility, hirsutism and increased cardiovascular risk factors. All these factors can negatively affect the health-related quality of life (HRQOL). The physical component of HRQOL is decreased by obesity, associations between body mass index (BMI) and the mental components of HRQOL vary, with either a decline or sometimes even improvement. While clinical features of PCOS are aggravated by obesity. However, reliable data is not available supporting the association between obesity and QOL of women with PCOS, while there are few studies reporting obesity as a main intermediator in the association between PCOS and declined HRQOL.
Obesity is believed to negatively affect the HRQOL of women with PCOS, not only because of the excess weight, but it also significantly affects their reproduction by causing anovulation, subfertility and irregular menses. A recent research has shown that body weight is directly linked to the worsening in all aspect of HRQOL. According another study, obesity is adversely associated with physical, but not mental HRQOL. Considering the severe adverse effects of excess body weight on HRQOL among individuals with metabolic disorders, and its impact on the reproductive characteristics of women with PCOS. The present study hypothesized that the association between excess weight on HRQOL in women with PCOS differ from those in healthy control. By comparing the effects of excess body weight on HRQOL between women with PCOS and their age and BMI matched counterparts.
Rationale behind research
- There is inconsistent data regarding the association between obesity and QOL of women with PCOS, with some studies reporting obesity as a main mediator in the PCOS-related declined HRQOL. While other studies document no relationship between obesity and HRQOL. This warrents the reason for conducting this study.
To compare the effects of excess body weight on the HRQOL between women with PCOS and controls.
- Study outcomes
HRQOL: HRQOL was assessed using short form health survey that included eight domains; physical functioning (PF), role limitation due to physical problem (RP), bodily pain (BP), general health perception (GH), vitality (VT), social functioning (SF), role limitation due to emotional problem (RE) and mental health (MH). These eight scales were pooled into two summary measures: the physical component summary scales (PCS) and mental component summary scales (MCS). Dimensions which were scored from 0 (minimum HRQOL) to 100 (good HRQOL with no defect). Validity and reliability of SF36 for Iranian populations was confirmed,with convergent validity ranging from 0.58 to 0.95 and Cronbach's alpha coefficients ranging from 0.77 to 0.90.
- All participants underwent clinical examinations to document body weight, height, waist (WC), hip circumferences(HC). Body mass index was measured as weight in kilograms, divided by the height in meters squared (kg/m²). The levels of BMI were classified as follows: BMI 18–24.9 kg/m² as normal, and BMI ≥25 kg/m² as overweight or obese.
- was assessed using the modified Ferriman Gallwey scoring method, by the main investigator (F.S) under supervision of a gynecologist
- The multivariate analysis for PCOS status showed wilks λ=0.035, F=4.64 and P<0.001; age, marital status, educational levels, BMI and parity had statistically significant effects on the HRQOL of controls. The effects of age, BMI and hirsutism on HRQOL of women with PCOS were also statistically significant.
- Univariate analysis showed that, compared to older women, those aged <30 years, had significantly higher PF and lower MH in cases and higher PF and BP in controls (P<0.05). In controls, the PCS for the younger age group (< 30 years) was significantly higher than those for the older age women (P=0.002). Unmarried controls had significantly higher PF, RP, BP, SF and PCS scores than married ones (P<0.05). There were a significant differences for BP in non-PCOS women; less educated women had significantly lower BP score of SF 36 than highly educated women (66.22±3.84 vs. 80.95±2.3 F=2.87 P=0.006). Healthy women with higher education had significantly higher PCS scores than less educated ones (77.67±1.37 vs. 71.43±2.47, P=0.029). For hirsutism, the univariate analysis showed significant differences for mental aspects of SF 36.
- Non-hirsute women with PCOS had significantly higher scores in VT, SF, MH, MCS, than hirsute women with PCOS. One-way Mancova analysis demonstrated significant effects of BMI on SF 36 scores after adjustment for age, parity, FG scores and period regularity (PCOS: Wilk’s λ=0.81, F=3.71, P< 0.001; non PCOS: Wilk’s λ=0.77, F=4.77, P<0.001); BP and PF domains of the SF 36 in cases and BP per se in controls were significantly higher in normal weight women than in overweight or obese ones (P<0.05). The multivariate effects for the two BMI categories were significant (PCOS: Wilk’s λ=0.92, F=5.2, P=0.007; non PCOS: Wilk’s λ=0.94, F=4, P=0.02). In both groups, the univariate analysis showed that the normal weight women had significantly higher PCS scores than overweight or obese ones (P< 0.05). In cases, a significant correlation was seen between BMI and PF, r = -0.301, P<0.001; BP, r = -0.23, P=0.006 and PCS r=-0.3, P=0.007. In controls, significant correlation was seen between BMI and BP, r=- 0.3, P<0.001 and PCS r=-0.27, P<0.00. The differences between PF correlations in the two groups were statistically significant using Fisher’s Z test (Z=-2.41, P=0.008).
Table 1: Comparisons of mean scores of health-related quality of life’s domains of women with polycystic ovary syndrome with controls.
This study showed that women with PCOS, compared to their age-BMI matched controls, had significantly lower scores, assessed by SF 36, in five domains of HRQO, VT, MH, SF, BP and GH. It was found that normal weight linked to higher scores for PF and BP and PCS in PCOS and for BP and PCS in the controls. The correlation between PF with BMI in women with PCOS was significantly different from those observed in controls; the negative impact of excess weight on physical domains of HRQOL in women with PCOS is stronger than in controls.
Results of the current study demonstrated that consequences of excess weight on the physical aspects of HRQOL varied between women with PCOS and healthy controls, results in agreement with those of a study that reported comorbidity of obesity had a greater impact on HRQOL. However our results differ from studies conducted mostly in western countries, showing a positive association between excess weight and reduction in the mental aspects of HRQOL.