Hyperinsulinemia and obese phenotype differently influence blood pressure in young normotensive patients with polycystic ovary syndrome

Association between insulin resistance and uncontrolled hypertension and arterial stiffness among US adults: a population-based study

BACKGROUND

Prior research has established the correlation between insulin resistance (IR) and hypertension. While the association between triglyceride-glucose (TyG) index, a reliable surrogate marker of IR, and uncontrolled hypertension as well as arterial stiffness among individuals with hypertension remains undisclosed.

METHODS

In this study, a total of 8513 adults diagnosed with hypertension from the National Health and Nutrition Examination Survey 1999-2018 were included. The primary outcome of the study are arterial stiffness (represented with estimated pulse wave velocity, ePWV) and uncontrolled hypertension. Logistic regression model, subgroup analysis, restricted cubic spine, and smooth curve fitting curve were conducted to evaluate the association between the IR indicators and uncontrolled hypertension and arterial stiffness in individuals with hypertension.

RESULTS

Among included participants, the overall prevalence of uncontrolled hypertension was 54.3%. After adjusting for all potential covariates, compared with the first quartile of TyG index, the risk of uncontrolled hypertension increased about 28% and 49% for participants in the third quartile (OR, 1.28; 95% CI 1.06-1.52) and the fourth quartile (OR, 1.49; 95% CI 1.21-1.89) of TyG index, respectively. The higher OR of TyG index was observed in participants taking antihypertensive medication [fourth quartile versus first quartile (OR, 2.03; 95% CI 1.37-3.11)]. Meanwhile, we explored the potential association between TyG index and arterial stiffness and found that TyG index was significantly associated with increased arterial stiffness (β for ePWV, 0.04; 95% CI 0.00-0.08; P = 0.039). However, traditional IR indicator HOMA-IR showed no significant positive correlation to uncontrolled hypertension as well as arterial stiffness in US adults with hypertension.

CONCLUSION

Elevated levels of the TyG index were positive associated with prevalence of uncontrolled hypertension and arterial stiffness among US adults with hypertension.

Risk factors for insulin resistance related to polycystic ovarian syndrome in Iranian population

Polycystic ovary syndrome (PCOS) has significant metabolic sequelae linked to insulin resistance. This study aimed to compare clinical, metabolic, and hormonal characteristics of PCOS women with and without insulin resistance. The second aim was to compare the clinico-biochemical profiles of the various PCOS phenotypes. In this cross-sectional secondary analysis, we combined the baseline data from two separate randomized controlled trials (RCTs) in women diagnosed with PCOS. PCOS patients were categorized into the four Rotterdam PCOS phenotypes according to the presence of at least two criteria of oligomenorrhea/anovulation (O), hyperandrogenism (H), and polycystic ovary morphology (P): O-H-P, H-P, O-H, and O-P. Participants were categorized into two groups according to the homeostasis model assessment index of insulin resistance (HOMA-IR) levels: < 3.46, and ≥ 3.46. The correlation between the HOMA-IR and biometric, clinical, and biochemical variables was assessed in normal weight (BMI < 25) and overweight/obese (BMI ≥ 25) PCOS women. Then, the association between PCOS phenotypes and insulin resistance was investigated using logistic regression analysis. A total of 125 PCOS patients aged 18-40 years were included in the present study. Based on our results, the HOMA-IR index was positively correlated with diastolic blood pressure, free androgen index, and triglycerides levels; and negatively correlated with sex hormone-binding globulin in overweight/obese PCOS women. In addition, the HOMA-IR index was found to be positively correlated with alanine transaminase and negatively correlated with diastolic blood pressure in normal weight PCOS women. Moreover, individuals with O-H-P phenotype (odds ratio [OR] 2.52, 95% confidence interval [CI] 1.02-6.24) had about two-fold increased risk of insulin resistance. In conclusion, the full-blown PCOS (O-H-P) phenotype has an increased risk of insulin resistance. Accordingly, phenotype division may help physicians to predict adverse metabolic outcomes.

Do Androgenic Pattern, Insulin State and Growth Hormone Affect Cardiorespiratory Fitness and Strength in Young Women with PCOS?

In this study, cardiorespiratory fitness (CRF) and strength level were assessed in women with and without polycystic ovary syndrome (PCOS), matched for age, body composition, androgenic pattern and insulinemic pattern. Patients with and without PCOS were evaluated at the Endocrinology Unit and Sport Medicine Division to assess endocrinological (insulinemic, androgenic pattern and growth hormone), anthropometric (with DEXA) and functional parameters (with cardiopulmonary exercise test and handgrip test), as well as physical activity level (with the Global Physical Activity Questionnaire). A total of 31 patients with PCOS and 13 controls were included. No statistically significant differences were found between groups in terms of age, body mass index, body composition, androgenic pattern, insulin state, growth hormone and physical activity level. The PCOS group demonstrated significantly better cardiorespiratory fitness (VO₂max per kg (30.9 ± 7.6 vs. 24.8 ± 4.1 mL/kg/min; p = 0.010), VO₂max per kg of fat-free mass (52.4 ± 8.9 vs. 45.3 ± 6.2 mL/kg/min; p = 0.018)), strength levels (handgrip per kg (0.36 ± 0.09 vs. 0.30 ± 0.08; p = 0.009), handgrip per kg of fat-free mass (13.03 ± 2.32 vs. 11.50 ± 1.91; p = 0.001)) and exercise capacity (METs at test (14.4 ± 2.72 vs. 12.5 ± 1.72 METs; p = 0.019)). In this study, women with PCOS showed a better cardiorespiratory fitness and strength than the control group. The only determinant that could explain the differences observed seems to be the presence of the syndrome itself. These results suggest that PCOS per se does not limit exercise capacity and does not exclude good functional capacity.

Poor sleep is associated with higher blood pressure and uterine artery pulsatility index in pregnancy: a prospective cohort study

OBJECTIVE

To elucidate the association between sleep disturbances and blood pressure as well as uterine artery Doppler during pregnancy in women with no pre-existing hypertension.

DESIGN

Prospective cohort study.

SETTING

Outpatient specialist clinics at KK Women's and Children's Hospital, Singapore.

POPULATION

Women with viable singleton pregnancies confirmed by ultrasonography at less than 14 weeks of amenorrhoea at first visit.

METHODS

In all, 926 subjects were recruited for this study in the outpatient specialist clinics at KK Women's and Children's Hospital, Singapore, between 1 September 2010 and 31 August 2014. They were followed up throughout pregnancy with sleep quality, blood pressure and uterine artery Doppler assessed at each visit.

MAIN OUTCOME MEASURES

Sleep quality, blood pressure and uterine artery Doppler.

RESULTS

Sleep progressively worsened as pregnancy advanced. Shorter sleep duration and poorer sleep efficiency were associated with higher blood pressure, especially in the first trimester. Mixed model analysis demonstrated an overall positive association between sleep quality represented by Pittsburgh Sleep Quality Index (PSQI) score and diastolic blood pressure (DBP) (P < 0.001) and mean arterial pressure (MAP) (P = 0.005) during pregnancy after considering all trimesters. Sleep duration was found to be negatively associated with both systolic blood pressure (SBP) (P = 0.029) and DBP (P = 0.002), whereas sleep efficiency was negatively correlated with DBP (P = 0.002) only. Overall poor sleep during pregnancy was also found to be associated with a higher uterine artery pulsatility index.

CONCLUSION

Our prospective study demonstrated that poor sleep quality is significantly associated with higher blood pressure and uterine artery pulsatility index during pregnancy.

TWEETABLE ABSTRACT

Poor sleep quality is significantly associated with higher blood pressure and higher uterine artery pulsatility index during pregnancy.

Higher blood pressure in normal weight women with PCOS compared to controls

OBJECTIVE

Obesity is considered to be the strongest predictive factor for cardio-metabolic risk in women with polycystic ovary syndrome (PCOS). The aim of the study was to compare blood pressure (BP) in normal weight women with PCOS and controls matched for age and BMI.

METHODS

From a Nordic cross-sectional base of 2615 individuals of Nordic ethnicity, we studied a sub cohort of 793 normal weight women with BMI < 25 kg/m2 (512 women with PCOS according to Rotterdam criteria and 281 age and BMI-matched controls). Participants underwent measurement of BP and body composition (BMI, waist-hip ratio), lipid status, and fasting BG. Data were presented as median (quartiles).

RESULTS

The median age for women with PCOS were 28 (25, 32) years and median BMI was 22.2 (20.7, 23.4) kg/m2. Systolic BP was 118 (109, 128) mmHg in women with PCOS compared to 110 (105, 120) mmHg in controls and diastolic BP was 74 (67, 81) vs 70 (64, 75) mmHg, both P < 0.001. The prevalence of women with BP ≥ 140/90 mmHg was 11.1% (57/512) in women with PCOS vs 1.8% (5/281) in controls, P < 0.001. In women ≥ 35 years the prevalence of BP ≥ 140/90 mmHg was comparable in women with PCOS and controls (12.7% vs 9.8%, P = 0.6). Using multiple regression analyses, the strongest association with BP was found for age, waist circumference, and total cholesterol in women with PCOS.

CONCLUSIONS

Normal weight women with PCOS have higher BP than controls. BP and metabolic screening are relevant also in young normal weight women with PCOS.

Pharmacological Approaches to Controlling Cardiometabolic Risk in Women with PCOS

Polycystic ovary syndrome (PCOS) is characterized by elevated androgen production and subclinical changes in cardiovascular and metabolic risk markers. Total cholesterol, high-density lipoprotein (HDL) cholesterol, fasting glucose, and fasting insulin appear to increase specifically in PCOS compared with fertile women. PCOS also confers an increased risk of cardiometabolic disease in later life. Novel biomarkers such as serum’s cholesterol efflux capacity and blood-derived macrophage activation profile may assist in more accurately defining the cardiometabolic risk profile in these women. Aldosterone antagonists, androgen receptor antagonists, 5α-reductase inhibitors, and synthetic progestogens are used to reduce hyperandrogenism. Because increased insulin secretion enhances ovarian androgen production, short-term treatment with metformin and other hypoglycemic agents results in significant weight loss, favorable metabolic changes, and testosterone reduction. The naturally occurring inositols display insulin-sensitizing effects and may be also used in this context because of their safety profile. Combined oral contraceptives represent the drug of choice for correction of androgen-related symptoms. Overall, PCOS management remains focused on specific targets including assessment and treatment of cardiometabolic risk, according to disease phenotypes. While new options are adding to established therapeutic approaches, a sometimes difficult balance between efficacy and safety of available medications has to be found in individual women.

Hypertension Risk in Young Women With Polycystic Ovary Syndrome: A Nationwide Population-Based Cohort Study

Objective: A number of publications have assessed the prevalence of hypertension in polycystic ovary syndrome (PCOS) patients with inconclusive results. Since in general populations the occurrence of hypertension is related to age and comorbidities, we investigated the incidence rate and hazard ratios (HRs) of hypertension between healthy subjects and young women with PCOS as well as comorbidities.

Methods: We conducted a population-based retrospective cohort study by using the National Health Insurance Research Database in Taiwan. The cohort included women with the diagnosis of PCOS between 2000 and 2012. Those without PCOS were selected as the control group at a ratio of 4:1 by an age-matched systematic random-sampling method. Cox proportional hazard regression analysis was used to determine the effects of PCOS on the risks of developing hypertension. Stratification analysis was performed to elucidate the interaction among PCOS and the comorbidities, which affect the incidence of hypertension.

Results: The PCOS cohort consisted of 20,652 patients with PCOS and the comparison cohort consisted of 82,608 matched patients without PCOS. There was no difference in the distribution of age between the PCOS cohort and the comparison cohort (29.1 ± 6.8 vs. 29.0 ± 6.5, p = 0.32). The incidence rates of hypertension were 7.85 and 4.23 per 1,000 person-years in the PCOS and comparison groups, respectively. A statistically significant higher risk of hypertension was found in the PCOS cohort (adjusted HR = 1.62, 95% confidence interval = 1.48–1.76) than in the comparison cohort. After a joint analysis of comorbidities, the adjusted HR of hypertension was 9.44 (95% confidence interval = 7.27–12.24) for PCOS patients with comorbidities of diabetes mellitus (DM) and hyperlipidemia compared with women with neither PCOS nor DM and hyperlipidemia.

Conclusion: The risk of developing hypertension in young women with PCOS was higher than in controls in this cohort study. The comorbidities of DM and hyperlipidemia could interact with PCOS patients and further increase the risk of hypertension. An earlier screening for hypertension and comorbidities in patients with PCOS may be warranted, even in young women.

Hyperinsulinemia rather than insulin resistance itself induces blood pressure elevation in high fat diet-fed rats

OBJECTIVE

To investigate if insulin resistance per se or the accompanying hyperinsulinemia induced hypertension and its underlying mechanisms.

METHODS

Sprague-Dawley rats were randomized into normal diet-fed group (ND group) and high-fat diet-fed group (HFD group). Then, the HFD group was further randomly divided into the control group (HFD_C group), the PIO group (treated with pioglitazone), the STZ_DM group (to induce diabetes with streptozotocin) and the DM+Ins group (streptozotocin injection followed by insulin treatment). Insulin sensitivity, plasma insulin, endothelin-1, norepinephrine, aldosterone, angiotensinⅡ and 24-h urinary sodium excretion (USE) levels of the groups were measured and analyzed. A multiple stepwise regression analysis method was applied to exam our hypothesis.

RESULTS

Compared to HFD_C group, the groups with lower plasma insulin, the PIO group and STZ_DM group, showed higher USE and lower blood pressure. The groups with higher plasma insulin (but same level of insulin resistance), the HFD_C group and DM+Ins group, showed lower USE and higher blood pressure. The 24-h urinary sodium excretion was the most important contributor to the significant changes of blood pressure with an R² of 25.2% in this animal experiment.

CONCLUSIONS

It is the compensatory hyperinsulinemia rather than insulin resistance per se that causes blood pressure elevation. The urinary sodium excretion is the key mediator among the multiple mechanisms. Therapies targeting hyperinsulinemia and restricting salt intake may favor a better control of hypertension associated with insulin resistance.

Nocturnal but not Diurnal Hypertension Is Associated to Insulin Resistance Markers in Subjects With Normal or Mildly Elevated Office Blood Pressure

OBJECTIVE

The aim was to evaluate the relationships among insulin resistance markers and nocturnal and diurnal hypertension in normotensive or mildly untreated hypertensive adults.

METHODS

The study was performed in both female and male adults referred to the Cardiometabolic Unit of the Hospital San Martín, La Plata, Argentina, in order to perform an ambulatory blood pressure measurement (ABPM) for the evaluation of a possible hypertensive disorder. The population was stratified according to their ABPM in: 1-presence or absence of diurnal hypertension and 2-presence or absence of nocturnal hypertension; both conditions were analyzed separately. Fasting plasma insulin (FPI), homeostasis model assessment of insulin resistance (HOMA-IR), and triglycerides (TG)/high-density lipoprotein cholesterol (HDL-C) ratio were used as surrogate markers of insulin resistance and compared among subjects with vs. without diurnal or nocturnal hypertension.

RESULTS

One hundred and five patients, 55 women, 47 (11) years old, and 50 men, 44 (16) years old, were included. Diurnal and nocturnal hypertension were found in 60% and 64% of the sample, respectively. There were no significant differences among the levels of insulin resistance markers between individuals with or without diurnal hypertension. In contrast, individuals with nocturnal hypertension were more insulin resistant irrespectively of whether they were evaluated using FPI (P = 0.016), HOMA-IR (P = 0.019), or TG/HDL-C ratio (P = 0.011); FPI differences remained significant after adjustment for sex, age, and obesity indicators (P = 0.032).

CONCLUSIONS

Nocturnal but not diurnal hypertension was related to higher levels of 3 insulin resistance markers in normotensive and untreated mildly hypertensive adults; this relationship seems partially independent of obesity.

Debates Regarding Lean Patients with Polycystic Ovary Syndrome: A Narrative Review

Polycystic ovary syndrome (PCOS) is a complex syndrome showing the clinical features of an endocrine/metabolic disorder, including hyperinsulinemia and hyperandrogenism. Two phenotypes are present, either lean or obese, with different biochemical, hormonal, and metabolic profiles. Evidence suggests many treatment modalities that can be applied. However, many of these modalities were found to be not suitable for the lean phenotype of PCOS. Much contradictory research was found regarding lean patients with PCOS. The aim of this narrative review is to shed light on the debate prevailing regarding characteristics, as well as metabolic, hematological, and potential management modalities. Literature review was performed from January 1, 2000 to March 31, 2017 with specific word search such as lean PCOS, hormonal abnormalities in lean PCOS, and the management of lean PCOS. All retrieved articles were carefully assessed, and data were obtained. We could conclude that the debate is still prevailing regarding this specific lean population with PCOS, especially with regard to their characteristics and management modalities. Further studies are still required to resolve this debate on the presence of PCOS in lean women.