Comparison of various simple insulin sensitivity and beta-cell function indices in lean hyperandrogenemic and normoandrogenemic young hirsute women

Exercise Interventions in Polycystic Ovary Syndrome: A Systematic Review and Meta-Analysis

Background: Polycystic ovary syndrome (PCOS) is a common and complex endocrinopathy with reproductive and metabolic manifestations. Exercise training has consistently been found to result in improved clinical outcomes in women with PCOS, but shortfalls with exercise prescription are evident. The aim of this systematic review and meta-analysis was to identify exercise intervention characteristics that provide favourable outcomes in women with PCOS.

Methods: A systematic review of published literature was conducted using EBSCOhost and Ovid Medline up to May 2019. The review adheres to the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) guidelines as per our PROSPERO protocol (CRD42018088367). Randomised controlled trials, non-randomised controlled trials, and uncontrolled trials that evaluated an exercise intervention of at least moderate intensity in women with PCOS were included. Meta-analyses were performed using general linear mixed modelling and Bayesian inferences about effect magnitudes.

Results: Thirty-three articles were identified for systematic review of which 19 were meta-analysed. Intervention duration ranged from 6 to 26 weeks. A total number of 777 women were included in the meta-analysis. The meta-analysis found that improvements in health outcomes are more dependent on exercise intensity rather than dose. Fixed effects analysis reported a moderate increase in VO_2peak (24.2%; 90% CL, 18.5–30.1), and small reductions in HOMA-IR (−36.2%; 90% CL, −55.3 to −9.0), and waist circumference (−4.2%; 90% CL −6.0 to −2.3) as a result of vigorous intensity exercise. These results are confirmed in the predicted analysis which reported the greatest improvements in VO_2peak, BMI, and waist circumference after vigorous intensity exercise alone or when combined with diet, particularly for women with clinically adverse baseline values.

Conclusions: Exercise training in the management of PCOS is becoming more common. Results from our analysis support the use of exercise and suggest that vigorous intensity exercise may have the greatest impact on cardiorespiratory fitness, body composition, and insulin resistance. Our results indicate that, a minimum of 120 min of vigorous intensity per week is needed to provide favourable health outcomes for women with PCOS with studies of longer duration required to evaluate outcomes with sustained exercise.

Should insulin resistance be screened in lean hirsute women?

The role of insulin resistance (IR) is well-documented in obese women with polycystic ovary syndrome (PCOS). Controversies exist concerning the presence of IR in idiopathic hirsutism (IH) or if it is a manifestation of high body mass index (BMI). We aimed to investigate the presence/absence of IR in lean hirsute women. One-hundred fifty-one lean women with hirsutism [96 PCOS (group 1) and 55 IH (group 2)] and 58 age-and BMI-matched healthy controls (group 3) were recruited in the study (mean age 25.21 ± 6.1 versus 26.26 ± 4.6years; BMI 21.79 ± 1.7 versus 22.02 ± 2.2 kg/m(2), respectively). Significantly higher insulin and HOMA-IR, and significantly lower fasting glucose insulin ratio (FGIR), quantitative insulin sensitivity check index (QUICKI), reciprocal insulin, and Raynaud index were detected in groups 1 and 2 than in group 3 (p < 0.05). These IR indices were similar between groups 1 and 2. The number of patients with IR (HOMA-IR > 2, FGIR < 7.2, or QUICKI < 0.357) was significantly higher in groups 1 and 2 than in group 3, but was similar between groups 1 and 2. A higher frequency of IR occurs in lean hirsute women regardless of they having PCOS or IH. IR may contribute to aetiopathogenesis of IH, or may cause some metabolic abnormalities in these patients.

The association of androgenetic alopecia and insulin resistance is independent of hyperandrogenemia: A case-control study

BACKGROUND/OBJECTIVES

Androgenetic alopecia (AGA) occurs due to the effect of androgens and genetic predisposition. The association between hyperandrogenism and insulin resistance (IR) has been clearly documented. In recent years there have been reports supporting the presence of IR in AGA. The study aimed to investigate the presence of IR in women with AGA and discern whether or not it is associated with hyperandrogenism.

METHODS

Overall, 77 women with AGA were included in the study. Patients with Ludwig grades I-III AGA were enrolled in the study. Blood samples were drawn for measurements of hormone profile, basal insulin and fasting blood glucose (FBG). An oral glucose tolerance test was performed on another day. IR was assessed by the homeostasis model assessment score.

RESULTS

All IR parameters were significantly higher in the 75 study subjects without DM than in the control group (P < 0.05). After excluding five patients with IGT, the level of all IR parameters were still higher than in the control group (P < 0.05). Hyperandrogenemia was found in 30 (40%) patients. When this second group (n = 45) (excluding patients with hyperandrogenemia) was compared with the control group on IR, all parameters except for basal insulin were significantly higher in the second group than in the controls (P < 0.05).

CONCLUSION

Our results suggest a relation between IR and AGA in female patients. We showed for the first time that the association of AGA and IR is independent of hyperandrogenemia.

The ratio of parathyroid hormone to vitamin D is a determinant of cardiovascular risk and insulin sensitivity in adolescent girls

BACKGROUND

Vitamin D insufficiency and higher testosterone are common in obese girls and may adversely affect glucose homeostasis and cardiovascular risk. Data are conflicting regarding the impact of parathyroid hormone (PTH) on these factors. Our objective was to determine associations of 25-hydroxyvitamin D (25-OHD), PTH, and testosterone with measures of glucose homeostasis and cardiovascular risk in adolescent girls after controlling for regional adiposity, with the hypothesis that lower 25-OHD, a higher PTH or PTH/25-OHD ratio, and higher testosterone would be associated with lower insulin sensitivity and greater cardiovascular risk.

METHODS

A total of 15 obese girls and 15 matched normal weight controls (12-18 years) underwent fasting measurements of 25-OHD, PTH, testosterone, sex hormone-binding globulin (SHBG), high-sensitivity C-reactive protein (hsCRP), oral glucose tolerance testing, and quantification of visceral (VAT) and subcutaneous (SAT) fat by magnetic resonance imaging (MRI).

RESULTS

There were no associations of 25-OHD with measures of glucose homeostasis or hsCRP. In contrast, PTH and PTH/25-OHD were associated negatively with homeostasis model assessment of insulin resistance (HOMA-IR) and positively with quantitative insulin sensitivity check index (QUICKI) in obese girls but not controls. These associations remained significant after controlling for body mass index standard deviation score (BMI-SDS), but not for VAT. On regression modeling, PTH/25-OHD was positively associated with hsCRP after controlling for BMI-SDS or VAT. Free testosterone positively predicted the corrected insulin response.

CONCLUSIONS

In obese girls, PTH/25-OHD is positively associated with measures of insulin sensitivity and hsCRP. Further studies are needed to investigate the relationship between PTH and glucose homeostasis in obesity.

Evaluation of various insulin sensitivity indices in lean idiopathic hirsutism patients

Hirsutism is characterized by excessive growth of terminal hair in a male pattern. Idiopathic hirsutism (IH) is a common cause of hirsutism. Since there are few data demonstrating IH is associated with insulin resistance, we tried to assess various insulin sensitivity indices in lean IH and compare with healthy subjects. A cross-sectional study was performed in 71 lean (BMI between 20-25 kg/m(2)) women (17-39 years old), 31 with IH and 40 healthy individuals. Blood glucose, insulin, homeostasis model assessment of insulin resistance (HOMA-IR), hepatic insulin sensitivity (ISI (HOMA)), Quicky index, reciprocal fasting insulin resistance index, fasting Belfiore index, and fasting glucose/insulin ration (GIR) were estimated using a single fasting sample of glucose and insulin levels. Raynaud indices calculated using the mathematical estimation in a single fasting sample of insulin levels were determined and compared in two groups. Fasting insulin, Raynaud index, HOMA-IR and Fasting insulin resistance index (FIRI) results were higher in IH group than in controls (p<0.01, for all). Fasting Belfiore index, QUICKI index, ISI(HOMA) and FIRI(-1) results were lower in IH group than in controls (p<0.01, for all). Our study showed that lean IH patients were more insulin resistant than healthy subjects. We propose that insulin sensitivity indices are useful methods for measuring insulin resistance in IH.

Subclinical impairment of left ventricular function in young obese women: contributions of polycystic ovary disease and insulin resistance

CONTEXT

Obesity and insulin resistance (IR) may produce disturbances of left ventricular (LV) function. Obese women with polycystic ovary syndrome (PCO), characterized by hormonal and metabolic abnormalities, are thought to be at particularly increased cardiovascular risk.

OBJECTIVES

We sought to determine the influence of IR on LV function in obese young women with and without PCO and without other comorbidities.

DESIGN

This was a cross-sectional study.

SETTING

The study was performed at a university hospital.

PATIENTS

A total of 150 women aged younger than 40 yr with a body mass index (BMI) of 30 kg/m(2) or more was classified into three groups: with both PCO and IR, without PCO and with IR, and without either PCO or IR.

MAIN OUTCOME MEASURES

Tissue Doppler-derived myocardial velocities, strain-rate and strain, and metabolic and hormonal measurements were calculated.

RESULTS

Subclinical impairment of LV systolic and diastolic function as indicated by lower peak strain (P < 0.001), peak systolic strain rate (P < 0.001), peak early diastolic strain rate (P < 0.001), and peak early diastolic velocity (P < 0.01) was demonstrated in both groups with IR. IR subjects with and without PCO did not differ in any LV function indices. Strain was independently associated with fasting insulin (beta = -0.39; P < 0.001), urinary albumin excretion (UAE) (beta = -0.36; P < 0.001), and BMI (beta = -0.22; P < 0.03), and peak early diastolic strain rate was associated with UAE (beta = -0.35; P < 0.001), fasting insulin (beta = -0.24; P < 0.02), BMI (beta = -0.23; P < 0.02), and SHBG (beta = 0.20; P < 0.04).

CONCLUSIONS

In obese young women, fasting insulin, BMI, SHBG, and UAE are independent correlates of impaired LV performance. The contribution of PCO to LV function abnormalities is linked to IR, but not to other hormonal aberrations associated with this condition.

Comparison of various insulin sensitivity indices in psoriatic patients and their relationship with type of psoriasis

AIM

We aimed to identify insulin resistance and its possible association with types, duration and severity of psoriasis, and to evaluate various simple insulin-sensitivity indices and beta-cell function in psoriasis.

METHODS

A cross-sectional study was performed in 110 non-obese adults (18-50 years old): 70 with psoriasis (53 type I, 17 type II psoriasis) and 40 healthy individuals. Blood glucose, insulin and C-peptide levels were measured. Oral glucose tolerance test (OGTT); insulin sensitivity and beta-cell function indices derived from a single sample and OGTT were determined and compared in three groups.

RESULTS

Total, type I and type II psoriatics had IGT rates of 18.6%, 13.2% and 40%, respectively. In the control group IGT was only 2.5%. Homeostasis Model Assessment (HOMA) beta cell index, fasting insulin, Raynaud index, HOMA-IR and FIRI results were higher in total, type I and type II psoriatics than in controls (P < 0.05, for all). Fasting Belfiore index, QUICKY index, ISI HOMA and FIRI(-1) results were lower in total, type I and type II psoriatics than in controls (P < 0.05, for all), and type I psoriatics had higher levels of these indices than type II psoriatics (P < 0.05, for all).

CONCLUSION

Our study showed that psoriatic patients were more insulin resistant than healthy subjects and type II psoriatics were more susceptible than type I psoriatics to develop IGT. We suggest that beta-cell function and insulin sensitivity indices are useful methods for measuring insulin resistance in psoriatics. We propose that OGTT should be applied especially in type II psoriatics because of increased rate of IGT in this group.

Prevalence of insulin resistance in the polycystic ovary syndrome using the homeostasis model assessment

OBJECTIVE

To determine the prevalence of insulin resistance (IR) in a large population of patients with the polycystic ovary syndrome (PCOS).

DESIGN

Prospective, case-control.

SETTING

University medical center.

PATIENT(S)

Two hundred seventy-one PCOS patients and 260 eumenorrheic, non-hirsute, control women.

INTERVENTION(S)

History and physical examination and blood sampling.

MAIN OUTCOME MEASURE(S)

Total T, free T, DHEAS, sex hormone-binding globulin, and fasting glucose and insulin levels; homeostatic model assessment values for IR (HOMA-IR) and percent beta-cell function (HOMA-%beta-cell).

RESULT(S)

Patients with PCOS and controls differed significantly in all parameters studied, except fasting glucose. Because the HOMA-IR and HOMA-%beta-cell values were variably associated with race, age, and body mass index, the HOMA-IR and HOMA-%beta-cell values were then adjusted for these cofounders. After adjustment, 64.4% of PCOS patients were noted to be insulin resistant, and 2.6% had beta-cell dysfunction. Compared with PCOS patients without IR (n = 96), patients with IR (n = 174) were more obese and had higher beta-cell function.

CONCLUSION(S)

In patients with PCOS, the prevalence of IR was 64% according to the HOMA-IR measurement, after adjustment. Patients with IR were more clinically affected. Although IR is a common abnormality in PCOS, it does not seem to be a universal feature.

The molecular-genetic basis of functional hyperandrogenism and the polycystic ovary syndrome

The genetic mechanisms underlying functional hyperandrogenism and the polycystic ovary syndrome (PCOS) remain largely unknown. Given the large number of genetic variants found in association with these disorders, the emerging picture is that of a complex multigenic trait in which environmental influences play an important role in the expression of the hyperandrogenic phenotype. Among others, genomic variants in genes related to the regulation of androgen biosynthesis and function, insulin resistance, and the metabolic syndrome, and proinflammatory genotypes may be involved in the genetic predisposition to functional hyperandrogenism and PCOS. The elucidation of the molecular genetic basis of these disorders has been burdened by the heterogeneity in the diagnostic criteria used to define PCOS, the limited sample size of the studies conducted to date, and the lack of precision in the identification of ethnic and environmental factors that trigger the development of hyperandrogenic disorders. Progress in this area requires adequately sized multicenter collaborative studies after standardization of the diagnostic criteria used to classify hyperandrogenic patients, in whom modifying environmental factors such as ethnicity, diet, and lifestyle are identified with precision. In addition to classic molecular genetic techniques such as linkage analysis in the form of a whole-genome scan and large case-control studies, promising genomic and proteomic approaches will be paramount to our understanding of the pathogenesis of functional hyperandrogenism and PCOS, allowing a more precise prevention, diagnosis, and treatment of these prevalent disorders.

Detecting insulin resistance in polycystic ovary syndrome: purposes and pitfalls

Approximately 50% to 70% of all women with polycystic ovary syndrome (PCOS) have some degree of insulin resistance, and this hormone insensitivity probably contributes to the hyperandrogenism that is responsible for the signs and symptoms of PCOS. Although uncertainty exists, early detection and treatment of insulin resistance in this population could ultimately reduce the incidence or severity of diabetes mellitus, dyslipidemia, hypertension, and cardiovascular disease. Even if that proves to be the case, there are still several problems with our current approach to insulin sensitivity assessment in PCOS, including the apparent lack of consensus on what defines PCOS and "normal" insulin sensitivity, ethnic and genetic variability, the presence of other factors contributing to insulin resistance such as obesity, stress, and aging, and concern about whether simplified models of insulin sensitivity have the precision to predict treatment needs, responses, and future morbidity. Although the hyperinsulinemic-euglycemic clamp technique is the gold standard for measuring insulin sensitivity, it is too expensive, time-consuming, and labor-intensive to be of practical use in an office setting. Homeostatic measurements (fasting glucose/insulin ratio or homeostatic model assessment [HOMA] value) and minimal model tests (particularly the oral glucose tolerance test [OGTT]) represent the easiest office-based assessments of insulin resistance in the PCOS patient. The OGTT is probably the best simple, office-based method to assess women with PCOS because it provides information about both insulin resistance and glucose intolerance. The diagnosis of glucose intolerance holds greater prognostic and treatment implications. All obese women with PCOS should be screened for the presence of insulin resistance by looking for other stigmata of the insulin resistance syndrome such as hypertension, dyslipidemia, central obesity, and glucose intolerance.