Is muscle mechanical function altered in polycystic ovary syndrome?

Toward a Robust Definition of Sport Sex

Elite individual sports in which success depends on power, speed, or endurance are conventionally divided into male and female events using traditional binary definitions of sex. Male puberty creates durable physical advantages due to the 20- to 30-fold increase in circulating testosterone producing a sustained uplift in men's muscle, bone, hemoglobin, and cardiorespiratory function resulting from male puberty and sustained during men's lives. These male physical advantages provide strong justification for a separate protected category of female events allowing women to achieve the fame and fortune from success they would be denied if competing against men. Recent wider social acceptance of transgender individuals, together with the less recognized involvement of intersex individuals, challenge and threaten to defeat the sex classifications for elite individual female events. This can create unfair advantages if seeking inclusion into elite female events of unmodified male-bodied athletes with female gender identity who have gained the physical advantages of male puberty. Based on reproductive physiology, this paper proposes a working definition of sport sex based primarily on an individual's experience of male puberty and can be applied to transgender and various XY intersex conditions. Consistent with the multidimensionality of biological sex (chromosomal, genetic, hormonal, anatomical sex), this definition may be viewed as a multistrand cable whose overall strength survives when any single strand weakens or fails, rather than as a unidimensional chain whose strength is only as good as its weakest link.

Evaluation of muscle and bone composition and function in aging women with polycystic ovary syndrome

OBJECTIVE

The potential effects of polycystic ovary syndrome (PCOS) on the musculoskeletal system are not well established. We examined the musculoskeletal system in women with PCOS in their late reproductive years.

STUDY-DESIGN

This cross-sectional study included 34 women with PCOS and 32 control women matched for age and body mass index (BMI).

MAIN OUTCOME MEASURES

Dual-energy x-ray absorptiometry (DXA) was used for body composition analysis and cross-sectional areas and fat fraction of muscles were assessed by magnetic resonance imaging-proton density fat fraction (MRI-PDFF) of the abdomen and thigh. Muscle strength was measured using an isokinetic dynamometer.

RESULTS

The mean age of the PCOS group was 43 ± 3.7 years and of the control group 42.2 ± 3.5 years. Testosterone, free androgen index, and fasting insulin were higher in PCOS patients than controls (p < 0.001, p = 0.001 and p = 0.032, respectively). Patients and controls had similar values for total abdominal muscle area (TAMA), paraspinal muscle area, thigh muscle area, vertebral MRI-PDFF, thigh and paraspinal muscle MRI-PDFF. There was no difference in DXA-derived muscle and bone composition between the two groups. Body composition parameters measured by MRI and DXA were correlated with BMI and fasting insulin levels, but not with androgen levels in both groups. Subgroup analyses showed that PCOS women with obesity had higher TAMA than controls with obesity (p = 0.012). Apart than higher 60°/sec knee extensor average power in nonobese PCOS (p = 0.049), no difference in muscle mechanical function was detected between PCOS patients and controls.

CONCLUSION

Musculoskeletal composition and function are similar in PCOS patients and healthy women in late reproductive years. Body composition is linked with obesity and insulin resistance rather than hyperandrogenemia.

Health-related physical fitness in women with polycystic ovary syndrome versus controls: a systematic review and meta-analysis

INTRODUCTION

Polycystic ovary syndrome (PCOS) is a common endocrinopathy associated with cardiometabolic dysfunction.

PURPOSE

(1) To compare HRPF indices, including cardiorespiratory fitness (CRF), muscle strength, and muscle endurance, between women with and without PCOS (i.e., controls). (2) To explore the impact of moderating factors, i.e., insulin sensitivity, androgen levels, physical activity levels, and body mass index, on these indices.

METHODS

Articles comparing HRPF between PCOS and control groups were identified until February 27th, 2022. Random-effects meta-analyses were conducted and moderating factors were explored with subgroup and meta-regression analyses.

RESULTS

Twenty studies were included. Compared to controls, CRF was lower in women with PCOS (n = 15, - 0.70 [- 1.35, - 0.05], P = 0.03, I2 = 95%). Meta-regression analyses demonstrated that fasting insulin (P = 0.004) and homeostatic model assessment of insulin resistance (P = 0.006) were negatively associated with CRF, while sex-hormone binding globulin levels (P = 0.003) were positively associated. Absolute muscle strength was not different between PCOS and controls (n = 7, 0.17 [- 0.10, 0.45], P = 0.22, I2 = 37%). One study evaluated muscle endurance and reported lower core endurance in PCOS subjects compared to controls.

CONCLUSION

These data suggest that PCOS may be associated with impaired CRF. It remains unclear whether muscle strength and endurance differ between women with PCOS and controls. As this data set was limited by a small sample size, potential for bias, and inconsistent findings, additional studies accounting for the heterogeneous presentation of PCOS as well as improved matching between PCOS and controls for characteristics known to affect HRPF would help elucidate the impact of PCOS on indices of HRPF.

PROSPERO REGISTRATION NUMBER

CRD42020196380.

Lean mass and associated factors in women with PCOS with different phenotypes

Although current evidence suggests increased risk of obesity, insulin resistance, and metabolic alterations in patients with polycystic ovary syndrome (PCOS), especially of a hyperandrogenic phenotype, the impact of each one of these variables on muscle mass remains uncertain. In this case-control study, we evaluated clinical and hormonal characteristics related to lean body mass according to the different PCOS phenotypes. We performed clinical, metabolic, and hormonal assessments and evaluated body compartments by dual-energy X-ray absorptiometry in 133 women of reproductive age. Creatinine served as an indirect marker of lean mass. Median age was 28 (range, 17-37) years. Women with phenotypes A and B (n = 59) had higher body mass index (BMI) and metabolic syndrome prevalence than those with phenotype C (n = 23) and controls (n = 51) (p<0.005). Women with phenotypes A and B also had higher Ferriman-Gallwey score (p<0.001), insulin levels (p = 0.006), HOMA-IR (p = 0.008), testosterone (p = 0.008), free androgen index (FAI) (p<0.001), fat mass index (FMI) (p = 0.015), android-to-gynoid fat ratio (p = 0.036), and bone mineral density (BMD) at lumbar spine (p = 0.027) and total femur (p = 0.013) than controls. Median appendicular lean mass index (ALMI) was higher in phenotypes A and B than in controls (7.01 [IQR, 6.33-8.02] vs. 6.69 [IQR, 5.94-7.09], p = 0.024), but it did not differ significantly from that in phenotype C (6.60 [IQR, 6.16-7.22], p = 0.222). Even after adjusting for BMI, ALMI correlated positively with creatinine in women with phenotypes A and B (rho = 0.319, p = 0.023) but not in those with phenotype C (p = 0.238) or controls (p = 0.097). In multivariate linear regression analyses, ALMI was positively associated with insulin, FAI, FMI, and total femur BMD. The present results suggest that fasting insulin, FAI, fat mass, and total femur BMD were positively associated with increased lean mass in women with PCOS phenotypes A and B.

Clinical Concerns on Sex Steroids Variability in Cisgender and Transgender Women Athletes

In the female athletic community, there are several endogenous and exogenous variables that influence the status of the hypothalamus-pituitary-ovarian axis and serum sex steroid hormones concentrations (e. g., 17β-estradiol, progesterone, androgens) and their effects. Moreover, female athletes with different sex chromosome abnormalities exist (e. g., 46XX, 46XY, and mosaicism). Due to the high variability of sex steroid hormones serum concentrations and responsiveness, female athletes may have different intra- and inter-individual biological and functional characteristics, health conditions, and sports-related health risks that can influence sports performance and eligibility. Consequently, biological, functional, and/or sex steroid differences may exist in the same and in between 46XX female athletes (e. g., ovarian rhythms, treated or untreated hypogonadism and hyperandrogenism), between 46XX and 46XY female athletes (e. g., treated or untreated hyperandrogenism/disorders of sexual differentiation), and between transgender women and eugonadal cisgender athletes. From a healthcare perspective, dedicated physicians need awareness, knowledge, and an understanding of sex steroid hormones' variability and related health concerns in female athletes to support physiologically healthy, safe, fair, and inclusive sports participation. In this narrative overview, we focus on the main clinical relationships between hypothalamus-pituitary-ovarian axis function, endogenous sex steroids and health status, health risks, and sports performance in the heterogeneous female athletic community.

Female Hyperandrogenism in Elite Sports and the Athletic Triad

Essential hyperandrogenism seems to be overrepresented in female elite athletes. This applies to mild forms such as polycystic ovary syndrome, as well as rare differences/disorders of sex development (DSD). The reason is likely a selection bias since there is increasing evidence that androgens are beneficial for athletic performance by potent anabolic effects on muscle mass and bone mass, and stimulation of erythropoiesis. XY DSD may cause a greatly increased production of testosterone in the male range, that is, 10 to 20 times higher than the normal female range. The established regulations concerning the eligibility of female athletes with severe hyperandrogenism to compete in the female classification remain controversial. The most common cause of menstrual disorders in female athletes, however, is probably an acquired functional hypothalamic disturbance due to energy deficiency in relation to energy expenditure, which could lead to low bone mineral density and increased risk of injury. This condition is particularly common in endurance and esthetic sports, where a lean body composition is considered an advantage for physical performance. It is important to carefully evaluate endocrine disturbances and menstrual disorders in athletes since the management should be specific according to the underlying cause.

Obesity, but not hyperandrogenism or insulin resistance, predicts skeletal muscle mass in reproductive-aged women with polycystic ovary syndrome: A systematic review and meta-analysis of 45 observational studies

Women with polycystic ovary syndrome (PCOS) exhibit reduced muscle insulin-mediated glucose uptake, potentially attributed to altered muscle mass; however, this is inconclusive. Altered muscle mass may aggravate PCOS complications. Our systematic review and meta-analysis evaluated whether PCOS alters muscle mass and function. Databases (MEDLINE, Web of Science, Scopus) were searched through September 2, 2020, for studies documenting skeletal muscle mass (lean tissue mass) and function (strength) in PCOS and control groups. The primary outcome was total lean body mass (LBM) or fat-free mass (FFM). Data were pooled by random-effects models and expressed as mean differences and 95% confidence intervals. Forty-five studies (n = 3676 participants) were eligible. Women with PCOS had increased total (0.83 [0.08,1.58] kg; p = 0.03; I²  = 72.0%) yet comparable trunk (0.84 [-0.37,2.05] kg; p = 0.15; I²  = 73.0%) LBM or FFM versus controls. Results of meta-regression analyses showed no associations between mean differences between groups in total testosterone or homeostatic model assessment of insulin resistance and total or trunk LBM or FFM (All: p ≥ 0.75). Mean differences in body mass index (BMI) were associated with total (0.65 [0.23,1.06] kg; p < 0.01; I²  = 56.9%) and trunk (0.56 [0.11,1.01] kg; p = 0.02; I²  = 42.8%) LBM or FFM. The PCOS subgroup with BMI ≥ 25 kg/m² had greater total LBM or FFM versus controls (1.58 [0.82,2.34] kg; p < 0.01; I²  = 64.0%) unlike the PCOS subgroup with BMI < 25 kg/m² (-0.45 [-1.94,1.05] kg; p = 0.53; I²  = 69.5%). Appendicular lean mass and muscle strength data were contradictory and described narratively, as meta-analyses were impossible. Women with PCOS have higher total and trunk lean tissue mass attributed to overweight/obesity, unlike hyperandrogenism or insulin resistance.

Gut Microbiota and Oral Contraceptive Use in Overweight and Obese Patients with Polycystic Ovary Syndrome

CONTEXT

Polycystic ovary syndrome (PCOS) is a common and complex endocrine disorder. Emerging animal and human data point to various changes in microbiota that could be linked with the syndrome. However, the effects of therapeutic approaches on gut microbial composition in women with PCOS remain unknown.

OBJECTIVE

We aimed to assess whether gut microbial composition is altered in PCOS and to determine the potential impact of oral contraceptive (OC) use on gut microbiota.

DESIGN

Prospective observational study.

SETTING

Tertiary referral hospital.

PATIENTS AND OTHER PARTICIPANTS

The study included 17 overweight/obese patients with PCOS and 15 age- and body mass index-matched healthy control women.

MAIN OUTCOME MEASURES

At baseline, clinical, hormonal, and metabolic evaluations and gut microbial composition assessment by 16S rRNA gene amplicon sequencing were performed for both groups. All measurements were repeated in patients after receiving an OC along with general lifestyle advice for 3 months.

RESULTS

Alpha and beta diversity did not show a difference between patients with PCOS and healthy controls at baseline and remained unaltered after 3 months of OC use in the PCOS group. Relative abundance of Ruminococcaceae was higher in PCOS (P = 0.006) and did not show a significant change after treatment.

CONCLUSION

Women with PCOS have an increased abundance of Ruminococcaceae, whereas short-term OC use does not alter compositional features of gut microbiota in the syndrome.

Osteosarcopenia in Reproductive-Aged Women with Polycystic Ovary Syndrome: A Multicenter Case-Control Study

CONTEXT

Osteosarcopenia (loss of skeletal muscle and bone mass and/or function usually associated with aging) shares pathophysiological mechanisms with polycystic ovary syndrome (PCOS). However, the relationship between osteosarcopenia and PCOS remains unclear.

OBJECTIVE

We evaluated skeletal muscle index% (SMI% = [appendicular muscle mass/weight (kg)] × 100) and bone mineral density (BMD) in PCOS (hyperandrogenism + oligoamenorrhea), and contrasted these musculoskeletal markers against 3 reproductive phenotypes (i): HA (hyperandrogenism + eumenorrhea) (ii); OA (normoandrogenic + oligoamenorrhea) and (iii), controls (normoandrogenic + eumenorrhea). Endocrine predictors of SMI% and BMD were evaluated across the groups.

DESIGN, SETTING, AND PARTICIPANTS

Multicenter case-control study of 203 women (18-48 years old) in New York State.

RESULTS

PCOS group exhibited reduced SMI% (mean [95% confidence interval (CI)]; 26.2% [25.1,27.3] vs 28.8% [27.7,29.8]), lower-extremity SMI% (57.6% [56.7,60.0] vs 62.5% [60.3,64.6]), and BMD (1.11 [1.08,1.14] vs 1.17 [1.14,1.20] g/cm2) compared to controls. PCOS group also had decreased upper (0.72 [0.70,0.74] vs 0.77 [0.75,0.79] g/cm2) and lower (1.13 [1.10,1.16] vs 1.19 [1.16,1.22] g/cm2) limb BMD compared to HA. Matsuda index was lower in PCOS vs controls and positively associated with SMI% in all groups (all Ps ≤ 0.05). Only controls showed associations between insulin-like growth factor (IGF) 1 and upper (r = 0.84) and lower (r = 0.72) limb BMD (all Ps < 0.01). Unlike in PCOS, IGF-binding protein 2 was associated with SMI% in controls (r = 0.45) and HA (r = 0.67), and with upper limb BMD (r = 0.98) in HA (all Ps < 0.05).

CONCLUSIONS

Women with PCOS exhibit early signs of osteosarcopenia when compared to controls likely attributed to disrupted insulin function. Understanding the degree of musculoskeletal deterioration in PCOS is critical for implementing targeted interventions that prevent and delay osteosarcopenia in this clinical population.

Tissue fat quantification by magnetic resonance imaging: proton density fat fraction in polycystic ovary syndrome

RESEARCH QUESTION

What are the potential differences between lean women with and without polycystic ovary syndrome (PCOS) in fat content in liver, vertebrae, paraspinal muscles, pancreas, subcutaneous (SCAT) and visceral adipose tissue (VAT)? Magnetic resonance imaging proton density fat fraction (PDFF) was used to establish these differences. This is a novel, non-invasive, operator-independent method with comparable diagnostic sensitivity and specificity to histologic examination for fatty liver disease, and strong correlation with muscle strength in neuromuscular studies.

DESIGN

Twenty lean women with PCOS (mean age 23.9 ± 2.3; body mass index [BMI] 22.4 ± 2.0) and 20 age- and BMI-matched healthy women (mean age 24.9 ± 1.5; BMI 21.5 ± 1.9) were enrolled in this cross-sectional study. Anthropometric, biochemical and hormonal evaluations along with magnetic resonance imaging proton density fat fraction were carried out.

RESULTS

PDFF% measurements of liver, SCAT and VAT were higher in the PCOS group, indicating increased fat content in these areas in lean women with PCOS compared with controls (P = 0.045, 0.030 and 0.037, respectively). In contrast, PDFF% values of vertebrae and paraspinal muscles in the PCOS group were lower than controls (P = 0.038 and 0.05, respectively). Pancreatic PDFF% measurements were similar between the groups. In the PCOS group, PDFF% of VAT was positively correlated with free androgen index (r = 0.69, P = 0.002).

CONCLUSIONS

PDFF% measurement, an MRI-based novel biomarker, reveals increased fat in liver, SCAT and VAT, and decreased fat in vertebral bones and paraspinal muscles of lean women with PCOS.

The Use of SenseWear Armband for Assessment of Daily Energy Expenditure and the Relation to Body Fat Distribution and Nutritional Intake in Lean Women with Polycystic Ovary Syndrome

OBJECTIVE

To evaluate nutritional intake, energy expenditure, and segmental body composition in lean women with polycystic ovary syndrome (PCOS) and compare them with age- and body mass index- (BMI-) matched control women.

METHODS

32 nonobese patients with PCOS and 31 age- and BMI-matched healthy women were included in the study. Energy expenditure and physical activity level were assessed by metabolic Holter equipment (SenseWear Armband, SWA) which was never previously used in lean PCOS population. Food intake is recorded with 24 hours of food record. Segmental body composition analysis was assessed by bioelectrical impedance analyses (BIA).

RESULTS

Mean BMI was 22.64 ± 3.64 and 21.55 ± 2.77 kg/m2 (p=0.185) in PCOS and control groups, respectively. Mean age was 22.03 ± 4.21 and 21.71 ± 2.67 year (p=0.720), respectively. No significant differences were found in total energy intake and percentage of carbohydrates, fats, and other micronutrients (p > 0.05). Energy percentage of proteins (%12.73 ± 1.98, p=0.008) was statistically lower in subjects versus the control group. The measurements of physical activity duration (PAD) (1.40 ± 0.87/2.18 ± 0.99 hours, p=0.002), active energy expenditure (372.35 ± 198.32/494.10 ± 186.50 kcal, p=0.018), and step counting (9370.03 ± 3587.49/11730.90 ± 3564.31 steps, p=0.013) measurement of the PCOS group were lower than the control group, respectively.

CONCLUSIONS

New diagnosed women with PCOS had similar distribution and quantity of body fat parameters and nutritional status when compared to healthy women. Control subjects were found more active in energy expenditure.