Thyroid and COVID-19: a review on pathophysiological, clinical and organizational aspects

BACKGROUND

Thyroid dysfunction has been observed in patients with COVID-19, and endocrinologists are requested to understand this clinical issue. Pandemic-related restrictions and reorganization of healthcare services may affect thyroid disease management.

OBJECTIVE AND METHODS

To analyze and discuss the relationship between COVID-19 and thyroid diseases from several perspectives. PubMed/MEDLINE, Google Scholar, Scopus, ClinicalTrial.gov were searched for this purpose by using free text words and medical subject headings as follows: "sars cov 2", "covid 19", "subacute thyroiditis", "atypical thyroiditis", "chronic thyroiditis", "hashimoto's thyroiditis", "graves' disease", "thyroid nodule", "differentiated thyroid cancer", "medullary thyroid cancer", "methimazole", "levothyroxine", "multikinase inhibitor", "remdesivir", "tocilizumab". Data were collected, analyzed, and discussed to answer the following clinical questions: "What evidence suggests that COVID-19 may induce detrimental consequences on thyroid function?"; "Could previous or concomitant thyroid diseases deteriorate the prognosis of COVID-19 once the infection has occurred?"; "Could medical management of thyroid diseases influence the clinical course of COVID-19?"; "Does medical management of COVID-19 interfere with thyroid function?"; "Are there defined strategies to better manage endocrine diseases despite restrictive measures and in-hospital and ambulatory activities reorganizations?".

RESULTS

SARS-CoV-2 may induce thyroid dysfunction that is usually reversible, including subclinical and atypical thyroiditis. Patients with baseline thyroid diseases are not at higher risk of contracting or transmitting SARS-CoV-2, and baseline thyroid dysfunction does not foster a worse progression of COVID-19. However, it is unclear whether low levels of free triiodothyronine, observed in seriously ill patients with COVID-19, may worsen the disease's clinical progression and, consequently, if triiodothyronine supplementation could be a tool for reducing this burden. Glucocorticoids and heparin may affect thyroid hormone secretion and measurement, respectively, leading to possible misdiagnosis of thyroid dysfunction in severe cases of COVID-19. High-risk thyroid nodules require a fine-needle aspiration without relevant delay, whereas other non-urgent diagnostic procedures and therapeutic interventions should be postponed.

DISCUSSION

Currently, we know that SARS-CoV-2 could lead to short-term and reversible thyroid dysfunction, but thyroid diseases seem not to affect the progression of COVID-19. Adequate management of patients with thyroid diseases remains essential during the pandemic, but it could be compromised because of healthcare service restrictions. Endocrine care centers should continuously recognize and classify priority cases for in-person visits and therapeutic procedures. Telemedicine may be a useful tool for managing patients not requiring in-person visits.

Platelet number is positively and independently associated with glycated hemoglobin in non-diabetic overweight and obese subjects

BACKGROUND AND AIMS

A significant increase in platelet count may be a risk factor for atherosclerotic cardiovascular disease. This study investigates the association between platelet number and glucose metabolism, evaluated by glycated hemoglobin (HbA1c) levels, in a apparently healthy population represented by overweight and obese subjects with normal glucose and HbA1c levels.

METHODS AND RESULTS

As many as 240 subjects, 177 women and 63 men, aged 18-70 years, were enrolled. Body mass index (BMI), waist circumference (WC), systolic and diastolic blood pressure levels, platelet count and fasting blood glucose, insulin, insulin resistance, HbA1c, uric acid, triglyceride, total cholesterol, high and low density lipoprotein cholesterol concentrations were evaluated. Concerning the univariate correlation analyses between platelets number and all other variables, platelet count was significantly (and positively) correlated only with HbA1c (P < 0.05) and female sex (P < 0.01). HbA1c (P < 0.05), female sex (P < 0.001), and diastolic blood pressure (P < 0.01), positively, and age (P < 0.05) and systolic blood pressure (P < 0.05), negatively, were significantly and independently associated to platelet count in a final multiple regression analysis.

CONCLUSION

This is the first study showing a strong positive and independent relationship between HbA1c and platelet number in non-diabetic overweight and obese subjects.

Platelet number is negatively and independently associated with carotid intima-media thickness in apparently healthy overweight/obese subjects

BACKGROUND AND AIM

A significant change of platelet number may be a risk factor for atherosclerotic cardiovascular disease. The aim of this study was to investigate the association between platelet number and early signs of atherosclerosis, evaluated by carotid intima-media thickness (c-IMT), in a apparently healthy population mainly represented by obese subjects.

METHODS AND RESULTS

As many as 961 subjects, 686 women and 275 men, aged between 18 and 74 years, were enrolled in the study. Of these, 54 individuals (5.6% of all subjects) were normal weight, 259 individuals (27.0% of all subjects) were overweight, and 648 individuals (67.4% of all subjects) were obese. Waist circumference (WC) and blood glucose, insulin, total cholesterol, high and low density lipoprotein cholesterol, triglycerides and platelet count were also detected in all subjects, who underwent carotid echo color doppler ultrasound to measure c-IMT. c-IMT was significantly and positively associated to age (r = 0.204, P < 0.0001), fasting glucose (r = 0.073, P < 0.0240), total cholesterol (r = 0.096, P = 0.0031), and systolic and diastolic blood pressure (r = 0.140, P < 0.0001 and r = 0.119, P < 0.0003 respectively); c-IMT was significantly and negatively correlated with platelet count (r = -0.165, P < 0.0001). Only age (P < 0.0001) and systolic blood pressure (P = 0.0393), positively, and platelet number (P < 0.0001), negatively, were significantly and independently associated to c-IMT in a final multiple regression analysis.

CONCLUSION

Lower platelet number represented an independent determinant of c-IMT in a population, mainly represented by obese patients. These results suggest that a decrease of platelet number may well be an early defensive mechanism in subjects developing the thickening of carotid artery.

Potential benefit of dehydroepiandrosterone supplementation for infertile but not poor responder patients in a IVF program

AIM

The aim of this paper was to evaluate the hypothesis that pretreatment with dehydroepiandrosterone (DEHA) may improve the result on in vitro fertilization (IVF) and the pregnancy outcome among infertile women with normal ovarian reserve.

METHODS

Double-blind, randomized, placebo-controlled study; 52 infertile patients received the long protocol IVF. Patients in Group 1, received 75 mg of DHEA once a day, 8 weeks before starting the IVF cycle and during treatment; control group (Group 2) received placebo. The primary endpoint was pregnancy, live birth and miscarriage rates, secondary endpoint was standard IVF parameters such us stimulation duration (hCG day), E2 on HCG-day, endometrial thickness, number of retrieved oocytes, metaphase II oocytes, embryos transferred and score of leading embryos transferred.

RESULTS

Patients in the DHEA group had a significantly higher live birth rate compared with controls (P<0.05). Miscarriage rate was higher in control group (P<0.05).

CONCLUSION

DHEA supplementation could have a beneficial effect on IVF outcome in infertile women with normal ovarian reserve.

Could androgen receptor gene CAG tract polymorphism affect spermatogenesis in men with idiopathic infertility?

PURPOSE

This study examined whether the AR-CAG repeat length might affect clinical characteristics (testis volume) seminal parameters (sperm count and its mobility) along with hormonal serum profile [FSH, LH, Testosterone (T) and Inhibin B (InhB)] both in idiopathic male infertility (IM) and in infertility due to a previous condition of cryptorchidism (CryM) or to Y chromosome long arm microdeletions (YM).

DESIGN

Observational study without intervention(s).

PATIENTS

One hundred and ten IM patients [90 idiopathic olizoospermic males (IOM) and 20 idiopathic azoospermic males (IAM)], 19 CryM male and 10 YM patients were included. Sixty-one age-matched healthy men who had fathered within 3 years were involved representing the control group (FM).

RESULTS

AR-CAG repeats stretch was significantly longer in IOM (p<0.05), CryM (p<0.05) and YM (p<0.001) than FM. When the AR-CAG repeat tracts were subdivided in three subgroups according to the length of CAG repeats tract assessed in fertile subjects (the one with the middle (n 19-21) belonging to the 25 and 75 % inter-quartile, the ends belonging to the <25 % inter-quartile and >75 % inter-quartile, respectively), there was a statistically significant difference of distribution of AR-CAG tract length among fertile and different groups of infertile men (p=<0.0005; chi-square test). Moreover, the subgroup of AR-CAG repeat stretch with 22-28 triplets was associated with lower levels of InhB both in idiopathic oligozoospermic (Scheffe, Bonferroni and Dunett tests p=<0.01) and azoospermic men (Scheffe, Bonferroni and Dunett test p=<0.05), while, when FM and men with idiopathic infertility were gathered in a single group, both the subgroup of AR- CAG tract with 15-18 repeats and the one with 22-28 repeats are associated with lower testis volume, reduced sperm count and serum InhB levels.

CONCLUSIONS

Our study showed that the outliers of AR-CAG repeat length seem to influence the function of AR, affecting testis volume and Sertoli cell function and consequently sperm production in both fertile and idiopathic infertile men.

Neurobehavioral studies, in transgenic F3/CONTACTIN (C57BL/6J × CBA) mice, on cognitive and anxiety aspects during late-adolescential period

OBJECTIVE

Besides than in the control of developmental events, axonal adhesive glycoproteins may be also involved in functions requiring fine organization and connectivity of the nervous tissue. We previously demonstrated morphological alterations and functional cerebellar deficits in transgenic mice (TAG/F3 mice) ectopically expressing the F3/Contactin axonal glycoprotein under the control of a selected regulatory region from the Transient Axonal Glycoprotein (TAG-1) gene. In the present study, the hippocampal function was explored by evaluating the ability of TAG/F3 mice to encode spatial and non-spatial relationships between discrete stimuli and to analyze an anxiety-related behavior.

MATERIALS AND METHODS

To the first end, mice were placed in an "open-Field" containing five objects and, after three sessions of habituation (S2-S4), their reactivity to objects displacement (S5-S4) and object substitution (S7-S6) was examined.To the second end, mice were placed in the "elevated zero maze", a standard test to explore the anxiety-related behavior, in order to study, in transgenic mice, the effects of F3 misexpression on emotional reactivity by measuring the avoidance of the unsheltered open sectors.

RESULTS

Statistical evaluations of reactivity to object novelty, TAG-F3 mice showed a lower DO exploration with respect to wild-type mice and, regarding DOs, TAG/F3 mice interacted less than wild-type mice, showing an impaired spatial change response. Furthermore, the number of HDIPS in transgenic TAG/F3 mice resulted significantly lower with respect to the controls (wild type).

CONCLUSIONS

These results indicate that the coordinated expression of axonal adhesive glycoproteins may be relevant for the functional maturation of the hippocampus.

Free triiodothyronine is associated with smoking habit, independently of obesity, body fat distribution, insulin, and metabolic parameters

BACKGROUND

The aim of this study was to examine the relationship between thyroid hormones and smoking and several other parameters like age, gender, insulin, and anthropometric and metabolic parameters in subjects with a wide range of body mass index (BMI).

PATIENTS AND METHODS

A total of 931 euthyroid normal weight (BMI<25.0 kg/m2), overweight and obese subjects (BMI ≥25.0 kg/m2), 663 women and 268 men, aged 18-68 yr, were investigated. Fasting TSH, free T3 (FT3), free T4 (FT4), insulin, glucose, and lipid serum levels were determined. Waist circumference was measured as an indirect parameter of central fat accumulation.

RESULTS

Smokers were younger (p<0.001) and showed higher FT3 (p<0.01), and triglyceride (p<0.01) levels and lower glucose (p<0.01) and HDL (p<0.001) concentrations than non smoking subjects. FT3 levels were directly associated with BMI (p<0.001), waist circumference (p<0.001), insulin (p<0.001), and triglyceride (p<0.01) levels and negatively correlated with age (p<0.001) and HDL-cholesterol levels (p<0.001). When a multiple regression analysis was performed with FT3 levels as the dependent variable, and smoking, age, gender, and TSH, insulin, triglyceride, and HDL-cholesterol serum concentrations as independent variables, FT3 levels maintained an independent positive association with smoking (p<0.05), age (p<0.001), male sex (p<0.001), waist circumference (p<0.05), and insulin levels (p<0.001).

CONCLUSIONS

Smoking increases FT3 levels independently of age, gender, obesity, body fat distribution and metabolic parameters.

Abdominal fat accumulation, and not insulin resistance, is associated to oligomenorrhea in non-hyperandrogenic overweight/obese women

BACKGROUND

There is a very high prevalence of obese women in the infertile population and many studies have highlighted the link between obesity and infertility. The aim of this study was to evaluate the prevalence of oligomenorrhea in uncomplicated obesity, and to examine whether this menstrual alteration is associated with anthropometric, hormonal, and metabolic parameters.

PATIENTS AND METHODS

This is a cross-sectional study of 266 overweight and obese body mass index (BMI) > or =25.0 kg x m(-2)] women, all having apparent normal fertility. Measurements included BMI, central fat accumulation (evaluated by waist circumference), blood pressure levels, and fasting insulin, glucose, and lipid (triglycerides, total and HDL-cholesterol) serum concentrations, and insulin resistance [estimated by (homeostasis model assessment) HOMAIR] during the early follicular phase (days 2-5 of the menstrual cycle).

RESULTS

One hundred and seventy-one (64.3%) of 266 women had normal menstrual cycles, 57 (21.4%) had oligomenorrhea, and 38 (14.3%) had hypermenorrhea and/or polimenorrhea. Women with oligomenorrhea had higher waist circumference, BMI, HOMAIR, and insulin levels than women with normal menstrual cycles. When association among oligomenorrhea and other variables (waist circumference, BMI, insulin and HOMAIR) was evaluated by logistic regression, and odds ratio was calculated per unit of SD increase, only waist circumference maintained a significant relationship with oligomenorrhea.

CONCLUSIONS

This study shows that more than 20% of women with simple obesity have oligomenorrhea, and suggests that central fat accumulation seems to have a possible direct role in this menstrual alteration, independently of hyperinsulinemia and/or insulin resistance.

Relation between adiponectin and bone mineral density in elderly post-menopausal women: role of body composition, leptin, insulin resistance, and dehydroepiandrosterone sulfate

INTRODUCTION

Adipocytokines have been proposed as new mediators of the protective effects of fat mass on the skeleton. The aim of this study was to test the relationship between adiponectin, leptin, and bone mineral density (BMD), independently of body composition, insulin resistance, and other factors known to affect bone metabolism.

METHODS

Thirty-six post-menopausal non-diabetic elderly women, with ages ranging from 66 to 77 yr took part in the study. In all subjects we evaluated body weight, height, body mass index (BMI), waist circumference, adiponectin, leptin, insulin, DHEAS, and homeostasis model assessment of insulin resistance (HOMA), as well as yr since menopause. Total body fat mass (FM) and BMD at whole body and femoral level were measured with Dual energy X-ray Absorptiometry (DXA). Volumetric BMD was defined as the ratio between total body BMD and height.

RESULTS

Leptin was positively and adiponectin negatively related with whole body and femoral BMD. Positive associations between insulin, HOMA, DHEAS, and BMD measures were also found. After adjusting for FM, only adiponectin maintained a significant relation with whole body and femoral BMD; the strength of this association was reduced after adjustment for insulin resistance, estimated by HOMA. In stepwise multiple linear regression analyses adiponectin explained 11.7% of total BMD variance, 17.4% of femoral neck BMD variance, and 30.7% of volumetric BMD variance, independently of BMI, FM, leptin, HOMA, and DHEAS.

CONCLUSIONS

The present study may suggest possible involvement of adiponectin in bone metabolism, independently of FM and insulin resistance even in elderly post-menopausal women.

sP-selectin plasma levels in obesity: association with insulin resistance and related metabolic and prothrombotic factors

BACKGROUND AND AIM

Soluble P-selectin (sP-sel) represents a marker of platelet activation. This study was addressed to investigate the associations of sP-sel plasma levels with anthropometric parameters, insulin resistance, and related metabolic and prothrombotic factors.

METHODS AND RESULTS

50 non-diabetic women, 17 with normal weight and 33 overweight and obese, aged 18-55 years, were examined. Measurements included body mass index (BMI), central fat accumulation (evaluated by waist circumference), systolic and diastolic blood pressure levels, fasting plasma concentrations of sP-sel, glucose, lipids (triglycerides, total cholesterol and HDL-cholesterol), insulin, and prothrombotic factors (plasminogen activator inhibitor-1, von Willebrand factor, fibrinogen), and insulin resistance (estimated by the homeostasis model assessment: HOMA(IR)). Overweight and obese women had higher fasting plasma sP-sel concentrations compared to normal-weight controls (P<0.05). sP-sel concentrations were positively correlated with BMI, HOMA(IR), systolic and diastolic blood pressure, fasting insulin, triglyceride and PAI-1 plasma levels (P<0.05 for all the correlations). When a multiple regression analysis was performed, with P-sel as dependent variable and all the other parameters as independent variables, P-sel did not maintain a significant relationship with any of these variables.

CONCLUSIONS

s-P-selectin plasma concentrations are higher in overweight and obese insulin resistant subjects, thus possibly contributing to the cardiovascular risk of these patients. However, body fatness and insulin resistance are not independent determinants of fasting plasma sP-sel concentrations.

Free triiodothyronine and thyroid stimulating hormone are directly associated with waist circumference, independently of insulin resistance, metabolic parameters and blood pressure in overweight and obese women

OBJECTIVE

To examine whether obesity, body fat distribution and insulin resistance have an independent effect on serum TSH and free thyroid hormones (FT3 and FT4) in a cohort of euthyroid women, represented by overweight and obese patients.

DESIGN AND PATIENTS

A total of 201 women, aged 18-68 years, with body mass index (BMI) > or = 25.0 kg/m(2) and TSH levels < 4.0 mU/l were investigated.

MEASUREMENTS

Fasting TSH, FT3, FT4, insulin, glucose, and serum lipid concentrations, and the level of insulin resistance, estimated by the homeostasis model assessment for insulin resistance (HOMA-IR). Waist circumference was measured as an indirect parameter of central fat accumulation.

RESULTS

FT3 was directly associated with BMI (P < 0.01) and waist circumference (P < 0.01), and negatively correlated with age (P < 0.001). FT4 was negatively associated with HOMA-IR (P < 0.05) and fasting insulin levels (P < 0.05). TSH was positively correlated with waist circumference (P < 0.05) and negatively associated with age (P < 0.05). When multiple regression analysis was performed with FT3 as the dependent variable, and waist circumference, HOMA-IR, blood pressure levels and serum lipid concentrations as independent variables, FT3 maintained an independent association only with waist circumference (positive, P < 0.05) and age (negative, P < 0.001). When multiple regression analysis was performed with TSH as the dependent variable, and the above parameters as independent variables, TSH maintained an independent association only with waist circumference (positive, P < 0.05) and age (negative, P < 0.05). By contrast, when multiple regression analysis was performed with FT4 as the dependent variable, FT4 did not maintain an independent association with any of the independent parameters.

CONCLUSIONS

Progressive central fat accumulation is associated with an increase in both FT3 and TSH serum levels, independently of insulin sensitivity, metabolic parameters and blood pressure. These results suggest that (1) progressive central fat accumulation is associated with a parallel increase in FT3 levels, possibly as an adaptive thermogenic phenomenon, and (2) the control of TSH secretion by free thyroid hormones is possibly impaired in obesity.

Haptoglobin serum levels are independently associated with insulinemia in overweight and obese women

BACKGROUND

Obesity is associated with a chronic low-grade inflammatory condition. Haptoglobin is a glycoprotein involved in the acute-phase response to inflammation, and it is increased in obese subjects. The possibility that hyperinsulinemia and/or insulin resistance may directly increase haptoglobin levels has never been tested. The aim of this study was to investigate the associations of haptoglobin serum levels with anthropometric parameters, insulin levels, insulin resistance and related metabolic variables in overweight and obese women.

PATIENTS AND METHODS

This is a cross-sectional study of 194 non-diabetic overweight and obese subjects, aged 18-68 yr. Measurements included body mass index (BMI), central fat accumulation [evaluated by waist circumference (WC)], systolic and diastolic blood pressure, and fasting concentrations of haptoglobin, insulin, glucose, lipids (triglycerides, total cholesterol, and HDL-cholesterol), and insulin resistance as estimated by the homeostasis model assessment (HOMAIR).

RESULTS

Haptoglobin serum levels showed a positive association with BMI (p<0.001), WC (p<0.001), HOMAIR (p<0.001), and fasting insulin (p<0.001), triglyceride (p<0.001) and glucose (p<0.05) blood levels. However, only insulin maintained a significant independent association with haptoglobin (p<0.001) when a multiple regression analysis was performed and age, BMI (or WC), blood pressure levels, HOMAIR, and fasting insulin, glucose, and lipid blood concentrations were entered as independent variables.

CONCLUSIONS

Higher haptoglobin serum levels seem to be a strong marker of hyperinsulinemia, independently of BMI, body fat distribution, insulin resistance and related parameters.

WNT10B mutations in human obesity

AIMS/HYPOTHESIS

Recent studies suggest that wingless-type MMTV integration site family, member 10B (WNT10B) may play a role in the negative regulation of adipocyte differentiation in vitro and in vivo. In order to determine whether mutations in WNT10B contribute to human obesity, we screened two independent populations of obese subjects for mutations in this gene.

SUBJECTS AND METHODS

We studied 96 subjects with severe obesity of early onset (less than 10 years of age) from the UK Genetics of Obesity Study and 115 obese Italian subjects of European origin.

RESULTS

One proband with early-onset obesity was found to be heterozygous for a C256Y mutation, which abrogated the ability of WNT10B to activate canonical WNT signalling and block adipogenesis and was not found in 600 control alleles. All relatives of the proband who carried this allele were either overweight or obese. Three other rare missense variants were found in obese probands, but these did not clearly cosegregate with obesity in family studies and one (P301S), which was found in three unrelated subjects with early-onset obesity, had normal functional properties.

CONCLUSIONS/INTERPRETATION

These mutations represent the first naturally occurring missense variants of WNT10B. While the pedigree analysis in the case of C256Y WNT10B does not provide definitive proof of a causal link of this variant with obesity, the finding of a non-functioning WNT10B allele in a human family affected by obesity should encourage further study of this gene in other obese populations.

Influence of subclinical hypothyroidism and T4 treatment on the prevalence and severity of obstructive sleep apnoea syndrome (OSAS)

BACKGROUND

Obstructive sleep apnoea (OSA) and subclinical hypothyroidism are relatively frequent disorders that may be causally linked. However, discordant results exist on the prevalence and severity of OSA in subclinical hypothyroidism. The aim of this study was to compare the prevalence and severity of sleep-disordered breathing in individuals with or without subclinical hypothyroidism, and to investigate the possible effect of levothyroxine treatment on these patients.

PATIENTS AND METHODS

One hundred and eight subjects were consecutively enrolled and divided in 3 groups, according to the TSH levels and levothyroxine therapy. The first group (Group A) was represented by 63 subjects with normal TSH and thyroid function. The other two groups included patients affected by subclinical hypothyroidism; one group (Group B) treated with levothyroxine, while the other group (Group C) was never treated with levothyroxine. Anthropometric, respiratory and polysomnographic data were evaluated in all individuals.

RESULTS

The percentage of OSA, neck circumference, and body mass index (BMI) were not statistically different among the 3 groups. Respiratory disturbance index (RDI) as well as the percentage of the total number of events (apnoea-hypopnoea) by total sleep time (TST) with <90% oxyhemoglobin saturation (TSTSaO2 <90%) were not different among the groups. When we observed OSA patients, the only significant difference between groups B and C was represented by the Epworth Sleepiness Scale (ESS) (p=0.005).

CONCLUSION

This study shows that subclinical hypothyroidism and treatment with levothyroxine do not influence the prevalence and severity of OSA, while sleep propensity is increased by untreated subclinical hypothyroidism.

Prevalence of obstructive sleep apnoea in a sample of obese women: effect of menopause

BACKGROUND

Obesity is a well known risk factor for obstructive sleep apnoea (OSA). Previous studies have investigated the prevalence of OSA among obese people, but a sample of women was rarely studied.

OBJECTIVE

To describe the anthropometric and polysomnographic characteristics of a sample of obese women and investigate the effect of menopause on the prevalence of OSA.

MATERIALS AND METHODS

Using a full-night polysomnography we studied a sample of 133 obese women with a body mass index (BMI) > or = 30 kg/m2.

RESULTS

About 44% of our sample had a respiratory disturbance index (RDI) > or = 10. Neck circumference, BMI and age resulted the strongest predictors of RDI value. We also found that the prevalence of OSA was higher among post-menopausal women (67%) in comparison with pre-menopausal women (31%). Moreover, post-menopausal women had larger neck circumference and higher waist-to-hip circumference ratio (WHR).

CONCLUSIONS

Among post-menopausal obese women the prevalence of OSA increases. We suggest that menopause could cause a different body fat distribution with an increase of fat in upper parts of the body and, consequently, with an increase of neck circumference.

High prevalence of previously unknown subclinical hypothyroidism in obese patients referred to a sleep clinic for sleep disordered breathing

BACKGROUND AND AIM

To evaluate the prevalence of previously unknown hypothyroidism in adult male and female patients with a wide range of body mass index (BMI) values, referred to a Sleep Clinic because of sleep disordered breathing (SDB).

METHODS AND RESULTS

Serum concentrations of thyroid stimulating hormone (TSH) and free thyroxin (fT4), as well as forced vital capacity (FVC), PaO2, PaCO2, the Epworth sleepiness scale (ESS), respiratory disturbance index (RDI), loud snoring, and the percentage of total sleep time (TST) with <90% oxyhemoglobin saturation (TST(saO2<90%)) were measured in 78 overweight and obese adult subjects with no previous diagnosis of hypothyroidism (age: 18-72 years). The prevalence of previously undiagnosed subclinical hypothyroidism in the population as a whole was 11.5%. BMI, TSH and ESS were significantly higher in the hypothyroid than the euthyroid subjects, but there was no significant between-group difference in RDI, TST(saO2<90%) or the other investigated variables, including the prevalence of obstructive sleep apnea (OSA). Among the hypothyroid individuals, BMI, neck circumference, ESS, RDI and TST(Sao2<90%) were significantly higher in those with than in those without OSA. Furthermore, there was a clear trend towards a lower FVC% and higher snoring score in the OSA patients.

CONCLUSIONS

Our results demonstrate a higher prevalence of hypothyroidism than that commonly reported in overweight and obese individuals referred to a Sleep Clinic for polysomnography because of SDB, thus suggesting that thyroid function should be evaluated in all obese patients suffering from SDB despite economic concerns.

Gender, age and menopause effects on the prevalence and the characteristics of obstructive sleep apnea in obesity

BACKGROUND

In the 1970s and 80s it was believed that obstructive sleep apnea (OSA) was primarily a disease of men. The present study was addressed to evaluate the effect of gender and menopause on the prevalence and the characteristics of OSA and on anthropometric, clinical, respiratory and polysomnographic data in a population of obese individuals.

PATIENTS AND METHODS

A total of 230 obese subjects (BMI >/= 30 kg m-2), 148 women and 82 men, aged 16-75 years, were recruited and evaluated for general and anthropometric parameters, respiratory function, sleep-related symptoms and sleep disorders of breathing.

RESULTS

Respiratory disturbance index (RDI) and the prevalence of OSA were lower in women than in men (P < 0.001 and P < 0.001, respectively). Among subjects < 55 years, neck circumference, percentage of predicted normal neck circumference (PPNC), waist-to-hip ratio (WHR), PaCO2, RDI and the prevalence of OSA were lower in female subjects (P = 0.05, P < 0.05, P < 0.001, P < 0.01 and P < 0.01, respectively). BMI, neck circumference, PPNC, WHR, RDI and the prevalence of OSA were higher in postmenopausal compared with premenopausal women (P < 0.01, P < 0.01, P < 0.01, P < 0.01 and P < 0.01, respectively).

CONCLUSIONS

Our study demonstrates that (i) the male dominance regarding the prevalence and the severity of OSA disappears in men older than 55 years, and (ii) menopause seems to play a pivotal role in modulating both the presence and the degree of sleep disorder.

Diurnal PaCO2 tension in obese women: relationship with sleep disordered breathing

OBJECTIVE

Several obese subjects show a wide array of respiratory disturbances during sleep due to an increased upper-airway resistance. The aim of the present study was to evaluate diurnal PaCO(2) tension in nonsmoking obese women and the possible relationship of this parameter with the presence of sleep disordered breathing (SDB).

DESIGN

Cross-sectional study of PaCO(2) tension in obese women.

PATIENTS AND METHODS

A total of 91 nonsmoking obese women (BMI > or =30 kg/m(2), aged 42.8+/-15.7 y) were recruited and evaluated for general and anthropometric parameters, respiratory function, sleep-related symptoms, and sleep disorders of breathing.

RESULTS

A total of 10 subjects (10.9%) had diurnal hypercapnia (PaCO(2)> or =43 mmHg). Age, BMI, neck circumference, apnoea/hypopnoea index, and nocturnal desaturation (expressed as TST(SaO(2<90%)); TST(SaO(2<90%))=percentage of total sleep time with oxyhaemoglobin saturation <90%) were significantly higher in obese patients with diurnal hypercapnia, compared to normocapnic women. Moreover, hypercapnic patients had reduced forced expiratory volume in 1 s compared to normocapnic individuals. By using multiple regression analysis, the best fitting model (r=0.62, P<0.001) for predicting diurnal PaCO(2) tension in the study population showed that 24.23% of the variance may be explained by TST(SaO(2<90%)), according to the equation: PaCO(2)=0.09 age+0.07 TST(SaO(2<90%))+33.00.

CONCLUSIONS

This study suggests that severity of SDB is the most important factor in determining diurnal PaCO(2) tension in apparently healthy nonsmoking obese women.

Effect of shift work on body mass index: results of a study performed in 319 glucose-tolerant men working in a Southern Italian industry

OBJECTIVE

To examine the influence of shift work on metabolic and cardiovascular risk factors in subjects working in an industry sited in Apulia, Southern Italy.

DESIGN

Cross-sectional study of metabolic effects of shift work in glucose tolerant workers in a chemical industry in southern Italy.

SUBJECTS

The subjects included 319 glucose tolerant male individuals, aged 35-60 y.

MEASUREMENTS

Anthropometric parameters (body mass index (BMI) and waist-to-hip ratio (WHR)), fasting concentrations of glucose, insulin, and lipids (total cholesterol, HDL-cholesterol, triglycerides), the sum of glucose levels during 75 g-oral glucose tolerance test (Sigma-OGTT), and systolic and diastolic blood pressure (SBP and DBP, respectively).

RESULTS

The prevalence of obesity was higher among shift workers compared to day workers, whereas body fat distribution was not different between the two groups. Shift workers had higher BMI than day workers, and shift working was associated with BMI, independently of age and work duration. Shift workers had significantly higher SBP levels, which were independently influenced by BMI, but not by shift work, thus suggesting that the difference in SBP may well be mediated by the increased body fatness.

CONCLUSION

In workers of an industry sited in Southern Italy, shift work may be directly responsible for increased body fatness and is indirectly associated with higher blood pressure levels and some features of metabolic syndrome.

Free testosterone plasma levels are negatively associated with the intima-media thickness of the common carotid artery in overweight and obese glucose-tolerant young adult men

OBJECTIVE

To evaluate the relation between free testosterone (FT) levels and the intima-media thickness of the common carotid artery (IMT-CCA) in overweight and obese glucose-tolerant (NGT) young adult men.

DESIGN

Cross-sectional study of FT and IMT-CCA in obese men.

SUBJECTS

A total of 127 overweight and obese NGT male individuals, aged 18-45 y.

MEASUREMENTS

FT plasma levels; IMT-CCA, as measured by high-resolution B-mode ultrasound imaging; central fat accumulation, as evaluated by waist circumference; body composition, as measured by bioimpedance analysis; insulin resistance, as calculated by homeostatic model assessment (HOMA(IR)); systolic and diastolic blood pressure; and fasting concentrations of glucose, insulin, and lipids.

RESULTS

IMT-CCA was positively correlated with age, body mass index (BMI), fat mass (FM), waist circumference, and fasting glucose concentrations, and inversely associated with FT levels. After multivariate analysis, IMT-CCA maintained an independent association with BMI, FM, and FT levels. This study indicates that IMT-CCA is negatively associated with FT levels, independent of age, total body fat, central fat accumulation, and fasting glucose concentrations in overweight and obese NGT patients.

CONCLUSION

Hypotestosteronemia may accelerate the development of atherosclerosis and increase the risk for CHD in obese men.

Low sleep quality and daytime sleepiness in obese patients without obstructive sleep apnoea syndrome

OBJECTIVES

To evaluate sleep quality, sleep-related symptoms, and degree of excessive daytime sleepiness (EDS) in severe obesity, independently of obstructive sleep apnoea syndrome (OSAS).

DESIGN

A cross-sectional study.

SETTING

Primary-care setting.

SUBJECTS, MAIN OUTCOME MEASURES

Anthropometric parameters, respiratory function data and sleep related symptoms were evaluated in 78 severely obese patients (aged 16-75 years) without OSAS and in 40 healthy sex- and age-matched normal weight subjects, who underwent a full-night polysomnography.

RESULTS

Obese patients and control subjects had similar sleep latency and rapid eye movement (REM) latency, but they showed lower percentage of REM (P < 0.01) and sleep efficiency (P < 0.05) than controls. All sleep-related symptoms (observed or reported apnoea, awakenings, choking and unrefreshing sleep) were significantly more frequent in obese patients than in control subjects. Loud snoring was present in 46.7% of the obese patients and in 8.1% of the control individuals (P < 0.01). Excess daytime sleepiness was reported by 34.7% of the obese patients and by 2.7% of the normal weight subjects (P < 0.01). The Epworth Sleepiness Scale (ESS) was higher in the obese group than in the control group (P < 0.01), whereas arousals were not different between the two groups.

CONCLUSIONS

This study clearly shows that severe obesity, even in the absence of OSAS, is associated with sleep-related disorders and EDS. All these alterations may be partly responsible for a lower quality of life, a higher prevalence of medical complications, an increased risk of occupational injury, and both social and family problems characterizing obese patients, independently of the presence of OSAS.

Fuel metabolism in adult individuals with a wide range of body mass index: effect of a family history of type 2 diabetes

OBJECTIVE

To evaluate whether a family history of Type 2 diabetes mellitus (T2DM) is associated with changes of fuel metabolism in normal glucose tolerant men and women with a wide range of BMI.

DESIGN

Cross-sectional study of resting energy expenditure (REE) and substrate oxidation in adult individuals.

SUBJECTS

Ninety-seven normal weight, overweight, and obese men and women, aged 18-45 years: 44 (38 pre-menopausal women and 6 men) with a first-degree family history of T2DM (FH+) and 53 (45 pre-menopausal women and 8 men) with no family history of T2DM (FH-).

MEASUREMENTS

REE, fat-free mass (FFM)-adjusted REE (REE/Kg FFM), respiratory quotient (RQ), substrate oxidation (carbohydrates, lipids, and proteins), energy intake, anthropometric parameters, body composition (evaluated by BIA), blood pressure, insulin sensitivity (as calculated by Homeostatic Model Assessment) and metabolic variables (fasting levels of insulin, glucose, and lipids).

RESULTS

REE, REE/Kg FFM, and lipid oxidation were lower, whereas carbohydrate oxidation and RQ were higher in FH+ than in FH- individuals.

CONCLUSIONS

This study suggests that a family history of T2DM decreases REE, REE/Kg FFM and lipid oxidation, thus possibly contributing to the development of obesity and to the adverse metabolic profile of subjects with a genetic background for T2DM.

Coagulation and fibrinolysis abnormalities in obesity

Abnormalities in coagulation and haemostasis represent a well-known link between obesity and thrombosis (both arterial and venous). Several studies have shown that obese patients have higher plasma concentrations of all pro-thrombotic factors (fibrinogen, vonWillebrand factor (vWF), and factor VII), as compared to non-obese controls, with a positive association with central fat. Similarly, plasma concentrations of plasminogen activator inhibitor-1 (PAI-1) have been shown to be higher in obese patients as compared to non-obese controls and to be directly correlated with visceral fat. Furthermore, obesity is characterized by higher plasma concentrations of anti-thrombotic factors, such as tissue-type plasminogen activator (t-PA) and protein C, as compared to non-obese controls, the increase in these factors being likely to represent a protective response partly counteracting the increase in pro-thrombotic factors. The issue of whether adipose tissue contributes directly to plasma PAI-1, its products stimulating other cells to produce PAI-1, or whether it primarily contributes indirectly has not yet been resolved. It has been proposed that the secretion of interleukin-6 (IL-6) by adipose tissue, combined with the actions of adipose tissue-expressed TNF-alpha in obesity, could underlie the association of insulin resistance with endothelial dysfunction, coagulopathy, and coronary heart disease. The role of leptin in impairing haemostasis and promoting thrombosis has been recently reported. Finally, some hormonal abnormalities (androgen, F, catecholamines) associated with the accumulation of body fat may contribute to the impairment of coagulative pathway in obesity. As to intervention strategies, dietary (i.e., low-fat high-fiber diet) and lifestyle (i.e., physical activity) measures have been demonstrated to be effective in improving the obesity-associated pro-thrombotic risk profile.

A family history of Type 2 diabetes is associated with increased plasma levels of C-reactive protein in non-smoking healthy adult women

AIMS

The aim of our study was to test whether a family history of Type 2 diabetes (FH) in women is associated with plasma C-reactive protein (CRP).

METHODS

CRP plasma levels were measured in 162 women, aged 18-60 years; 95 had a positive family history of Type 2 diabetes in a parent or grandparent (FH+), and 67 gave no family history of this disease (FH-). Other measurements included: central fat accumulation, as evaluated by waist circumference; insulin resistance, as calculated by homeostatic model assessment (HOMAIR); systolic and diastolic blood pressure; and fasting concentrations of glucose, insulin, and lipids.

RESULTS

CRP plasma levels were significantly higher in FH+ than in FH- subjects. Moreover, CRP was independently associated with age, body mass index, waist circumference, HOMAIR, and FH.

CONCLUSIONS

Our study, performed in a selected population of women free from well-known risk factors for atherothrombosis, demonstrates that subjects with a family history of Type 2 diabetes have higher CRP plasma levels than age- and BMI-matched controls with no family history. Our results show that a family history of Type 2 diabetes is an independent contributor of CRP concentrations, in addition to age, total fatness, central fat accumulation, and insulin resistance.

Clinical and endocrinological effects of 6 months of metformin treatment in young hyperinsulinemic patients affected by polycystic ovary syndrome

Most patients with polycystic ovary syndrome (PCOS) have hyperinsulinemia; thus it has been postulated that insulin-lowering drugs, such as metformin, might be a useful long-term choice. We evaluated the effects of 6 months' administration of metformin on clinical and endocrine indices in PCOS patients. Forty-two hyperinsulinemic women with PCOS were continuously treated with metformin for 6 months. Gonadotropins, androgens (testosterone and androstenedione), insulin, sex hormone binding globulin (SHBG), lipid profile and clinical indices (menstrual length, body mass index (BMI), Ferriman-Gallwey score and waist/hip ratio (WHR)) were studied before and after metformin treatment. All women experienced a normalization of menstrual cycle length (reduction rate, 36.9%), a significant decrease in luteinizing hormone, insulin and androgen levels and an increase in SHBG plasma concentrations, with a concomitant decrease in cycle length and WHR. Significant changes were observed in the lipid profile. According to baseline androgen levels, patients were divided into two groups: 20 normoandrogenic and 17 hyperandrogenic women. The greatest decline of androgens, BMI and Ferriman-Gallwey score was observed in hyperandrogenic patients. Lowering of androgenicity was independent of BMI. Significant changes in lipid profile were observed in both groups after metformin treatment. These results suggest that metformin is effective in decreasing hyperandrogenism, mainly by reducing insulin levels. This leads to an improvement of clinical manifestations of PCOS and, in particular, of hyperandrogenism.

Impairment of albumin and whole body postprandial protein synthesis in compensated liver cirrhosis

To investigate the anabolic effects of feeding in cirrhosis, we measured albumin fractional synthesis rate (FSR) and whole body protein synthesis in six nondiabetic patients with stable liver cirrhosis (three in the Child-Pugh classification Class A, three in Class B) and in seven normal control subjects, before and after administration of a 4-h mixed meal. Leucine tracer precursor-product relationships and whole body kinetics were employed at steady state. Basal levels of postabsorptive albumin concentration and FSR, whole body leucine rate of appearance, oxidation, and nonoxidative leucine disposal (NOLD, approximately equal to protein synthesis) were similar in the two groups. However, after the meal, in the patients neither albumin FSR (from 8.5 +/- 1.5 to 8.8 +/- 1.8 %/day) nor NOLD (from 1.69 +/- 0.22 to 1.55 +/- 0.26 micromol x kg(-1) x min(-1)) changed (P = nonsignificant vs. basal), whereas they increased in control subjects (albumin FSR: from 10.9 +/- 1.5 to 15.9 +/- 1.9 %/day, P < 0.002; NOLD: from 1.80 +/- 0.14 to 2.10 +/- 0.19 micromol x kg(-1) x min(-1), P = 0.032). Thus mixed meal ingestion did not stimulate either albumin FSR or whole body protein synthesis in compensated liver cirrhosis. The mechanism(s) maintaining normoalbuminemia at this disease stage need to be further investigated.

Sleep-related breathing disorders, loud snoring and excessive daytime sleepiness in obese subjects

OBJECTIVE

To investigate the prevalence of sleep breathing disorders, loud snoring and excessive daytime sleepiness in a group of obese subjects, and to identify the predictors of obstructive sleep apnea (OSA) severity in these patients.

SUBJECTS

A total of 161 consecutive obese patients (body mass index (BMI)> or =30.0 kg/m(2)), ranging between 30.0 and 67.3, represented by 57 men and 104 women, aged 16-75 y. Forty (15 men and 25 women) age-matched (20-70 y) nonobese (BMI<27 kg/m(2)) volunteers were also recruited for the study.

MEASUREMENTS

Respiratory function parameters, nocturnal sleep quality (evaluated by a specific questionnaire), nocturnal hypoventilation and OSA (evaluated by night polysomnography) were examined in all subjects. Anthropometric parameters (neck circumference, waist circumference, waist-to-hip ratio) were also investigated.

RESULTS

Eighty-three obese patients (51.5% of the obese group) had a respiratory disturbance index (RDI)> or =10, corresponding to a moderate or severe sleep apnea. In particular, 24.8% (40/161), ie a quarter of all obese patients, were affected by severe OSA and this alteration was present in 42.1% of obese men (24/57) and in 15.4% (16/104) of obese women. When a stepwise multiple regression analysis was performed, neck circumference in men and BMI in women were shown to be the strongest predictors of sleep apnea. Twenty-nine percent of all obese subjects (40.3% of men and 23.1% of women) showed nocturnal hypoventilation; however, it was present as a unique breathing alteration in only 5% of the obese population. The percentage of patients having excessive daytime sleepiness was significantly higher than in nonobese subjects, even when only nonapneic obese patients were considered (P<0.001).

CONCLUSION

This study shows that OSA is present in more than 50% of a population of obese patients with a mean BMI higher than 40.0, this percentage being much higher than that commonly reported in previous studies, particularly in women. Neck circumference in men and BMI in women seem to be the strongest predictors of the severity of OSA in obese patients. Nocturnal hypoventilation seems to be present in more than 29% of a severe obese population. Moreover, this study indicates that morbid obesity can be associated with excessive daytime sleepiness even in the absence of sleep apnea.

Urinary albumin excretion is independently associated with C-reactive protein levels in overweight and obese nondiabetic premenopausal women

OBJECTIVES

C-reactive protein (CRP) and microalbuminuria are nowadays considered markers of chronic inflammation of the arterial wall and of endothelial dysfunction, respectively. An increase of CRP levels and of urinary albumin excretion (UAE) rate have both been reported to be independently associated with a higher risk of cardiovascular morbidity and mortality in the general population. The aim of the present study was to evaluate the possible correlation between UAE and CRP concentrations in overweight and obese premenopausal women.

DESIGN AND SETTING

A cross-sectional study in a primary care setting.

SUBJECTS, MAIN OUTCOME MEASURES

CRP levels and UAE rate were measured in 103 overweight and obese premenopausal women, aged 18-45 years. Other measurements included: central fat accumulation, as evaluated by waist circumference, insulin resistance, as calculated by homeostatic model assessment (HOMAIR); fat-free mass (FFM), as measured by bioimpedance analysis; blood pressure; and fasting plasma levels of glucose, insulin, and lipids.

RESULTS

Urinary albumin excretion was positively correlated with body mass index (BMI) (P < 0.01), waist circumference (P < 0.001), diastolic blood pressure (P < 0.01), triglycerides (P < 0.01), HOMAIR (P < 0.05), and CRP levels (P < 0.05); and negatively associated with HDL cholesterol (P < 0.001). After multivariate analysis, diastolic blood pressure, HDL cholesterol, and CRP levels maintained their significant correlation with UAE.

CONCLUSION

Our study shows a strong relationship between UAE and CRP concentrations, irrespective of age and other anthropometric and metabolic variables. On this basis, it can be argued that inflammation of the arterial wall, as indicated by higher CRP plasma levels, and endothelial dysfunction, as shown by higher UAE rate, might represent simultaneous phenomena in the development of atherosclerosis in overweight and obese premenopausal women.

Role of the 4G/5G polymorphism of PaI-1 gene promoter on PaI-1 levels in obese patients: influence of fat distribution and insulin-resistance

As PAI-1, a cardiovascular risk factor linked to insulin-resistance, may be influenced by a 4G/5G gene polymorphism in disease states, we studied both PAI-1 plasma concentration (PAI-1:Ag) and 4G/5G polymorphism, and their relationship with anthropometric and endocrinemetabolic parameters in 93 obese patients and 79 lean normal subjects. In obese patients PAI-1:Ag levels were significantly increased, namely in males and in those with central obesity, and tightly related to the insulin-resistance parameters. In obese patients the 4G/5G polymorphism was a determinant of PAI-1:Ag levels, which were highest in 4G/4G, intermediate in 4G/5G and lowest in 5G/5G genotype carriers. PAI-1:Ag levels were significantly associated with most of anthropometric and endocrine-metabolic parameters only in 4G allele obese carriers. Moreover, only in patients with central obesity was the relationship between genotype and PAI-1 concentration maintained, with the highest levels in the 4G/4G patients. In each genotype subset of patients with central, but not peripheral, obesity PAI-1:Ag levels were significantly increased compared to their lean counterparts. In conclusion, the 4G/5G polymorphism may influence PAI-1 expression in obesity, with a crucial role in central but not peripheral adiposity. Since subjects with central obesity are at high risk for cardiovascular disease, the effects of the 4G/5G polymorphism on PAI-1 concentration may further enhance this risk.

C-reactive protein is independently associated with total body fat, central fat, and insulin resistance in adult women

OBJECTIVE

To investigate whether C-reactive protein (CRP) concentrations are influenced by body composition, insulin resistance, and body fat distribution in healthy women.

DESIGN

Cross-sectional study of CRP plasma levels in adult women.

SUBJECTS

A total of 201 apparently healthy normal weight, overweight, and obese women, aged 18-60 y.

MEASUREMENTS

CRP plasma levels, several fatness and body fat distribution parameters (by bioimpedance analysis and anthropometry), and insulin resistance (HOMA(IR)), as calculated by homeostatic model assessment.

RESULTS

CRP was positively correlated with age, body mass index (BMI), waist, fasting glucose and insulin, HOMA(IR), fat-free mass (FFM) and fat mass (FM). After multivariate analyses, age, HOMA(IR), waist and FM maintained their independent association with CRP.

CONCLUSION

Our study has shown an independent relationship of central fat accumulation and insulin resistance with CRP plasma levels, thus suggesting that mild, chronic inflammation may be a further component of the metabolic syndrome and a mediator of the atherogenic profile of this syndrome.

Homocysteine plasma levels are independently associated with insulin resistance in normal weight, overweight and obese pre-menopausal women

OBJECTIVES

The aim of the present study was to examine the relationship of homocysteine (Hcy) plasma levels to insulin resistance (IR).

DESIGN

A cross-sectional study in a primary care setting.

SUBJECTS AND METHODS

Fasting Hcy levels were measured in the plasma of 44 pre-menopausal women [17 normal weight (body mass index BMI 20.0-24.9 kg/m2), 7 overweight (BMI 25.0-29.9 kg/m2), 20 obese (BMI> or =30.0 kg/m2)], aged 18-45 yr. Other measurements included: central fat accumulation, as evaluated by waist circumference; IR, as calculated by homeostatic model assessment (HOMAIR); systolic and diastolic blood pressure; and fasting concentrations of glucose, insulin and lipids (total cholesterol, HDL-cholesterol, triglycerides).

RESULTS

Hcy was positively correlated with insulin concentrations (p<0.01), HOMAIR (p<0.01), and systolic and diastolic blood pressure (p<0.01 and p<0.05, respectively). After multivariate analysis, only HOMAIR maintained an independent association with Hcy (p<0.05), irrespective of age and other anthropometric and biochemical variables. Lastly, we observed a gradual increase in Hcy plasma levels across the age- and BMI-matched quartiles in which the whole population was divided according to HOMAIR levels (F: 2.73, p<0.05 for linear trend).

CONCLUSIONS

Our study shows that Hcy plasma levels are independently associated with IR in apparently healthy normal weight, overweight and obese pre-menopausal women, thus suggesting a possible role of IR and/or hyperinsulinaemia in increasing Hcy plasma levels. Since Hcy is a well-known cardiovascular risk factor, higher Hcy plasma levels may well be a further mechanism explaining the higher risk of coronary heart disease in patients affected by IR.

Plasma leptin is independently associated with the intima-media thickness of the common carotid artery

OBJECTIVE

To investigate whether intima-media thickness (IMT) of the common carotid artery (CCA), an early marker of asymptomatic atherosclerosis, is significantly and independently associated with plasma concentrations of leptin, an adipose tissue hormone that has recently been proposed as a cardiovascular risk factor in obese patients.

DESIGN

Cross-sectional sample of normal-weight and obese men and women.

SUBJECTS

One-hundred and twenty healthy subjects (52 men and 68 women), aged 18-45 y and with a wide range of BMI, were recruited for the study.

MEASUREMENTS

Fasting plasma leptin concentrations and the IMT of the CCA were measured in all subjects. Leptin concentrations were measured by radioimmunoassay and the IMT of the CCA was quantified by high resolution B-mode ultrasound imaging. Central fat (measured by waist circumference), smoking habits, blood pressure, insulin sensitivity (measured by the insulin tolerance test), and fasting plasma glucose, insulin and lipid pattern (cholesterol, HDL-cholesterol, triglycerides, LDL-cholesterol) were also measured.

RESULTS

IMT of the CCA was positively correlated with log leptin concentrations (P<0.005 in men and P<0.001 in women), body mass index (P<0.001 in men and women), waist circumference (P<0.001 in men and women), age (P<0.001 in men and P<0.05 in women), and negatively associated with insulin sensitivity in both sexes (P<0.05). IMT was also directly correlated with cholesterol (P<0.05), LDL-cholesterol (P<0.01) and systolic blood pressure in men (P<0.05), and with diastolic blood pressure levels in women (P<0.05). When a multiple linear regression model was used without body mass index (BMI), the correlation between leptin and IMT was maintained in both men (P<0.01) and women (P<0.005), independent of age, insulin sensitivity, smoking habits, systolic blood pressure, fasting glucose, triglycerides, cholesterol, LDL-cholesterol and HDL-cholesterol. By contrast, BMI-adjusted leptin concentrations were not significantly associated with IMT (Pc (partial correlation): 0.41 in men and 0.15 in women). Moreover, when BMI was entered into a multiple linear regression model without leptin, the correlation between BMI and IMT was maintained in both men (P<0.005) and women (P<0.01), independent of the same parameters.

CONCLUSION

Plasma leptin concentrations are independently associated with the IMT of the CCA, suggesting that the increase of adipose tissue mass (or leptin per se) may have an unfavourable influence on the development of atherosclerosis. However, the association between IMT and leptin seems to be dependent and/or confounded by the relationship between IMT and obesity.

Lower insulin sensitivity as an independent risk factor for carotid wall thickening in normotensive, non-diabetic, non-smoking normal weight and obese premenopausal women

OBJECTIVE

Increased thickness of the intima-media complex of the common carotid artery (IMT-CCA) is an early marker of atherosclerosis. The aim of the present study was to investigate the relationship between insulin resistance and IMT-CCA in premenopausal women.

SUBJECTS

86 young women, aged 18-31 y, were recruited for the study: 28 were normal weight (BMI<25 kg/m2), 23 were overweight (BMI 25-30 kg/m2) and 35 were obese (BMI>30 kg/m2).

MEASUREMENTS

The IMT-CCA was measured by high resolution 'B-mode' ultrasonography; insulin sensitivity was determined by insulin tolerance test (ITT) and quantitated by calculation of KITT. Fasting plasma glucose and lipids (triglycerides, total and HDL-cholesterol) were also measured by enzymatic methods. Central fat accumulation was evaluated by measuring waist circumference (WC).

RESULTS

IMT-CCA showed an inverse association with KITT (P<0.05). When the IMT-CCA was considered as the dependent variable in a forward stepwise multiple regression analysis, it maintained an independent association with KITT (P<0.05), after adjusting data for age, BMI, WC, mean blood pressure levels and plasma glucose and lipids.

CONCLUSION

These results suggest that IMT-CCA is significantly associated with insulin resistance, independent of other well-known CVD risk factors. Since the IMT-CCA is an earlier asymptomatic sign of atherosclerosis, this study indicates that insulin resistance per se may accelerate atherogenesis.

Resting energy expenditure, growth hormone indices, body composition and adipose tissue distribution in premenopausal women

OBJECTIVES

A significant growth hormone (GH) contribution to interindividual variance in energy expenditure (REE) in women can be hypothesized. The present study examines the independent association between physiological levels of GH function indices and REE.

SETTING

All subjects were hospitalized in the Institute of Internal Medicine of the University of Verona.

SUBJECTS

Twenty-four premenopausal overweight (BMI = 28-55 kg m-2) women aged 18-49 years.

INTERVENTIONS

REE was estimated by indirect calorimetry and body composition and fat distribution by single slice computed tomography method. GH activity and GH status were determined by measuring serum levels of insulin-like growth factor I (IGF-I) and insulin-like growth factor binding protein-3 (IGFBP-3).

RESULTS

GH indices did not show any significant correlation with REE. The relation between GH indices and REE was also examined by multiple regression analysis to account for possible confounders such as body composition, adipose tissue distribution and age. When body composition was considered, body fat and fat-free mass were the only significant predictors of REE (R2 = 0.699, P = 0.0001). The contributions of GH indices were not significant.

CONCLUSIONS

Our findings do not support the hypothesis that GH in physiological conditions could be an independent determinant of REE in women with obesity.

The adipose tissue metabolism: role of testosterone and dehydroepiandrosterone

Testosterone (T) and dehydroepiandrosterone (DHEA) are fat-reducing hormones, even though they exert this effect by different mechanisms. In particular, T inhibits lipid uptake and lipoprotein-lipase (LDL) activity in adipocytes, and stimulates lipolysis by increasing the number of lipolytic beta-adrenergic receptors. An indirect sign of these effects is the decrease of adipocyte leptin production. Lastly, T inhibits differentiation of adipocyte precursor cells. Concerning DHEA, this hormone does not seen to have any of T effects; however, DHEA stimulates resting metabolic rate (RMR) and lipid oxidation, and enhances glucose disposal, by increasing the expression of GLUT-1 and GLUT-4 on fat cell plasma membrane. The insulin-like effect of DHEA would be associated to a decrease of plasma insulin concentrations and, thus, to an increase of the molar ratio between lipolytic hormones and insulin. Noteworthy, the fat-reducing effect of both T and DHEA seems to be more evident at the level of visceral adipose tissue.

Comparison of Diane 35 and Diane 35 plus finasteride in the treatment of hirsutism

OBJECTIVE

To compare the clinical efficacy of an original combined therapy with cyproterone acetate, 2 mg, and ethinylestradiol, 35 microgram (Diane 35), plus finasteride (5 mg) for 2 weeks per month with that of Diane 35 alone in hirsute women.

DESIGN

Prospective randomized, single-blinded study.

SETTING

Outpatients in an academic research environment.

PATIENT(S)

Fifty women with idiopathic hirsutism (IH) or the polycystic ovary syndrome (PCOS).

INTERVENTION(S)

Group 1 (n = 25) received Diane 35 alone and group 2 (n = 25) received Diane 35 plus finasteride. The latter drug was administered using a new therapeutic scheme: 14 consecutive days for each therapeutic cycle.

MAIN OUTCOME MEASURE(S)

Hormonal evaluation was done before beginning treatment and after 3 and 6 months of therapy. Hirsutism was graded at 3-month intervals.

RESULT(S)

The combination of Diane 35 plus finasteride for 14 days significantly decreased the hirsutism score after 3 months of therapy, while Diane 35 alone induced this effect after 6 months.

CONCLUSION(S)

Finasteride in combination with Diane 35 for 14 days is effective, well accepted, and safe in hirsute patients, as the amount of antiandrogenic drugs administered is much lower than that in conventional treatment.

Microcirculatory damage of common carotid artery wall in obese and non obese subjects

The objective of the present study was to determine whether the intima-media thickness (IMT) is independently related with obesity, and central fat accumulation in healthy subjects. Common carotid artery IMT, parameters of body fat accumulation and distribution (body mass index, waist circumference, waist-to-hip ratio), blood pressure levels, and circulating fasting insulin, glucose, and lipid (cholesterol, HDL-cholesterol, triglycerides, LDL-cholesterol) levels were determined in a population of non-diabetic normal weight and obese subjects. Smoking habits (packs-years) were also taken into account. 239 healthy subjects (143 women and 96 men), with age ranging between 18 and 45 years, were enrolled into the study. They were divided indo two groups according to the body mass index (BMI), obese (132 subjects, 77 woman and 55 men, with BMI greater than 27.0) and controls (107 subjects: 66 women and 41 men, with BMI lower than 27.0). Common carotid artery intima-media thickness was measured by B-mode ultrasound imaging. Fasting plasma metabolic parameters (glucose and lipids) and insulin levels were determined by enzymatic and radioimmunological assays, respectively. Insulin sensitivity was estimated by insulin tolerance test (ITT) and the rate constant for plasma glucose disappearance (KITT) during the 3- to 15-min period following the regular insulin injection was taken as a measure of in vivo insulin action. Obese patients showed higher IMT than controls, and IMT was significantly associated with BMI in the whole population (r = 0.316, p < 0.001). Age (r = 0.327, p < 0.001), KITT (r = -0.201, p < 0.01), fasting blood glucose (r = 0.187, p < 0.01), LDL-chol (r = 0.201, p < 0.01), smoking (r = 0.147, p < 0.05), MBP levels (r = 0.154, p < 0.05), cholesterol (r = 0.152, p < 0.05) and HDL-chol (r = -0.159, p < 0.05) were also significantly associated with IMT. Age (r = 0.330, p < 0.05), BMI (r = 0.299, p < 0.01), waist (r = 0.312, p < 0.001), WHR (r = 0.266, p < 0.001) and KITT (r = -0.259, p < 0.01) were the parameters most strongly correlated with IMT in women, and age (r = 0.324, p < 0.001), BMI (r = 0.338, p < 0.001) waist (r = 0.325, p < 0.001) and LDL-chol (r = 0.283, p < 0.01) where the parameters most strongly correlated with IMT in men. When a stepwise multiple regression analysis was performed for the whole population, only age (p < 0.001) and BMI (p < 0.001) maintained a significant positive relationship with IMT. When a stepwise multiple regression analysis was performed separately for men and women, BMI or waist circumference or WHR were alternatively entered into the model; interestingly, only age, BMI and waist were still significantly correlated with IMT, whereas WHR did not maintain a significant correlation with IMT. In conclusion, BMI and waist circumference, but not WHR, are strongly and independently associated with the IMT of common carotid artery. These results suggests that central fat accumulation may accelerate the development of earlier clinically silent stages of atherosclerosis, thus possibly explaining the higher prevalence of cardiovascular diseases in patients with abdominal obesity.

Prevalence and mechanisms of diurnal hypercapnia in a sample of morbidly obese subjects with obstructive sleep apnoea

It is well known that obstructive sleep apnoea is especially frequent in the morbidly obese. In these subjects diurnal chronic hypercapnia, whose mechanism is still debated, may be present. Our study was performed to evaluate the prevalence and the mechanism of diurnal hypercapnia in the morbidly obese affected by obstructive sleep apnoea. From a population referred to our centre because of suspicion of sleep related breathing disorders, we selected 285 subjects without cardiopulmonary, neuromuscular or endocrinological diseases: 89 (36 M and 53 F, aged 46+/-13 years) had body mass index (BMI) > or = 40 kg m(-2) (MO group: morbidly obese subjects) and 196 (99 M and 97 F, aged 48+/-16 years) had BMI <40 kg m(-2) (NMO group: non-morbidly obese subjects). Then the MO group was divided into three subgroups: normocapnic subjects without obstructive sleep apnoea, normocapnic subjects with obstructive sleep apnoea, hypercapnic subjects with obstructive sleep apnoea; while we found no hypercapnic subject without obstructive sleep apnoea. All subjects underwent anthropometric evaluations and bioelectrical impedance analyses, respiratory function tests and arterial blood gas analysis, a modified version of the Sleep and Healthy questionnaire and a full night polysomnography. Our results showed that hypercapnia (PaCO2 > or = 45 mm Hg) associated with obstructive sleep apnoea [respiratory disturbance index (RDI) > or = 10 h(-1)] was found in 27% of the morbidly obese subjects, but only in 11% of the nonmorbidly obese ones (P<0.01). The comparison among the three subgroups, in which we divided the morbidly obese subjects, shows that those with hypercapnia and obstructive sleep apnoea had significantly more important ventilatory restrictive defects [forced vital capacity (FVC)% of pred 73.27+/-14 81 vs. 82.37+/-16.93 vs. 87.25+/-18.14 respectively; total lung capacity (TLC)% of pred 63.83+/-16.35 vs. 79.11+/-14.15 vs. 87.01+/-10.5], a significantly higher respiratory disturbance index (RDI 46.34+/-26.90 vs. 31.79+/-22.47 vs. 4.98+/-3.29) a longer total sleep time with oxyhaemoglobin saturation<90% [total sleeptime (TST)SaO2<90% 63.40+/-33.86 vs. 25.95+/-29.34 vs. 8.22+/-22.12] and a lower rapid eye movement (REM) stage (9.5+/-1.2 vs. 14.0+/-0.9 vs. 17.05+/-1.2) than normocapnic subjects with obstructive sleep apnoea or subjects without obstructive sleep apnoea. The best model to predict PaCO2 resulted from a combination of TSTSaO2<90% (r2 = 0.22, P<0.001), forced expiratory volume in 1 sec (FEV1)% of pred (r2 = 0.09, P<0.01), FVC % of pred (r2 = 0.075, P<0.01). In conclusion our study suggests that diurnal hypercapnia is frequently associated with obstructive sleep apnoea in the morbidly obese without chronic obstructive pulmonary disorder (COPD) and that ventilatory restriction and sleep related respiratory disturbances correlate to diurnal hypercapnia.

Beneficial effects of postmenopausal hormone replacement therapy with transdermal estradiol on sensitivity to activated protein C

Many hemostatic and fibrinolytic parameters have been evaluated following hormone replacement therapy (HRT) but little is known about its influence on the anticoagulant response to activated protein C (APC-sensitivity). For this purpose, we studied the effect of transdermal 17-beta-estradiol (50 microg/24 h) by a continuous regimen on the APC-sensitivity, in 28 postmenopausal hysterectomized women (mean age, 47 years; range, 44-65 years). We also measured the plasma proteins directly involved in the protein C anticoagulant pathway, such as activities of factor VIII (VIII:C), factor V and free protein S. Von Willebrand factor (vWF) antigen, the carrier protein of factor VIII, was also determined. Blood sampling was done at baseline and after 16-week therapy. A significant increase in the normalized APC-sensitivity ratio (n-APC-SR) values (mean +/- SD: pre-trial, 0.88 +/- 0.14; post-trial, 1.01 +/- 0.12; P < 0.001) and a significant decrease of factor VIII:C plasma levels (pre-trial, 1.13 +/- 0.29 IU/ml; post-trial, 0.98 +/- 0.20 IU/ ml; P = 0.001) were found. No difference was observed in factor V, protein S and vWF plasma levels. Correlation studies demonstrated only a significant negative correlation between the percent change in n-APC-SR and the percent change in factor VIII:C (r = -0.574; P = 0.001). Our findings clearly show that HRT with transdermal estradiol improves the anticoagulant response to APC, probably as a result of a decreased factor VIII:C. We also suggest that a similar but opposite mechanism may occur for perorally administered estrogens used in the HRT. These results may have some clinical implications about the reported increase of the risk for venous thromboembolism following HRT.

Plasma plasminogen activator inhibitor-I is associated with plasma leptin irrespective of body mass index, body fat mass, and plasma insulin and metabolic parameters in premenopausal women

Leptin, the satiety hormone expressed almost exclusively in adipose tissue, is a marker of body fat accumulation in humans. Recent studies have shown that plasminogen activator inhibitor-1 (PAI-1), a prothrombotic factor associated with atherosclerosis complications, is also produced in adipose tissue. The objective of the present study was to determine whether PAI-1 antigen plasma concentrations are associated with leptin plasma levels or the body fat mass (FM) independently of the variables known to influence PAI-1 production. Sixty-one nondiabetic women aged 18 to 45 years with a wide range of values for the body mass index ([BMI] 18.1 to 37.7 kg/m2) were evaluated for (1) body FM and fasting plasma levels of (2) PAI-1 antigen, (3) PAI-1 activity, (4) leptin, (5) insulin, (6) blood glucose, and (7) lipids (cholesterol, high-density lipoprotein [HDL]-cholesterol, and triglycerides [TG]). Body FM and fat-free mass (FFM) were estimated during fasting conditions by the bioimpedance analysis (BIA) method using a tetrapolar device. Body fat distribution was evaluated by the waist circumference and the waist to hip ratio (WHR). FM was directly associated with both PAI-1 antigen (r = .585, P < .001) and PAI-1 activity (r = .339, P < .001). Seemingly, leptin was positively related to both PAI-1 antigen (r = .630, P < .001) and PAI-1 activity (r = .497, P < .001). Moreover, both PAI-I antigen and PAI-1 activity were directly correlated with FFM (r = .285, P < .05, and r = .336, P < .01, respectively), BMI (r = .594, P < .001, and r = .458, P < .001, respectively), and WHR (r = .510, P < .001, and r = .391, P < .005, respectively). Insulin was directly related to PAI-1 antigen (r = .540, P < .001), PAI-1 activity (r = .259, P < .05), leptin (r = .447, P < .001), and FM (r = .435, P < .001). The association between PAI-1 antigen (dependent variable) and leptin or FM was tested by a stepwise regression model simultaneously including leptin, FM, BMI, WHR, age, FFM, and fasting insulin, blood glucose, TG, cholesterol, and HDL-cholesterol as independent variables. PAI-1 antigen maintained a significant positive independent relationship only with leptin (t = 2.923, P < .01), insulin (t = 3.489, P < .001), and fasting blood glucose (t = 2.092, P < .05), and a negative independent relationship with HDL-cholesterol (t = -2.634, P < .05). In conclusion, the strong relationship between PAI-1 antigen and leptin irrespective of other variables known to influence these factors seems to indicate that leptin per se may potentially increase PAI-1 plasma concentrations in obese subjects.

Divergent effects of short-term, very-low-calorie diet on insulin-like growth factor-I and insulin-like growth factor binding protein-3 serum concentrations in premenopausal women with obesity

OBJECTIVE

Insulin-like growth factor-I (IGF-I) and insulin-like growth factor binding protein-3 (IGFBP-3) serum concentrations provide a good measure of the biological effects of growth hormone. The aims of the present study were to: (1) investigate the associations of IGF-I and IGFBP-3 with body fat mass and distribution, and (2) evaluate the effects of 3 weeks of very-low-calorie diet (VLCD) (318 kcal/day, with 40 g protein, 35 g carbohydrate, and 2 g fat) on IGF-I and IGFBP-3 serum concentrations.

RESEARCH METHODS AND PROCEDURES

The study was performed in 21 nondiabetic premenopausal women with obesity (body mass index >27.0 kg/m2; age: ranging from 18 to 48 years). Body fat mass and distribution were measured by computed tomography.

RESULTS

Before dietary treatment, IGF-I and IGFBP-3 serum concentrations were inversely associated with visceral adipose tissue (VAT) area (p<0.005 and p<0.05, respectively), but not with either total body fat or subcutaneous adipose tissue area. VLCD produced a significant decrease of body mass index (p<0.001), total body fat (p<0.001), VAT (p<0.005), subcutaneous adipose tissue (p<0.001), IGF-I concentrations (p<0.05), and an increase of IGFBP-3 serum levels (p<0.001). The association of VAT with either IGF-I or IGFBP-3 serum concentrations was not maintained following VLCD.

DISCUSSION

Our study suggests that visceral adipose tissue, rather than adiposity per se, accounts for IGF-I and IGFBP-3 serum concentrations, and that rapid weight loss, possibly due to nutritional changes, results in lower IGF-I concentrations, higher IGFBP-3 concentrations, and abrogation of the inverse associations of VAT with IGF-I and IGFBP-3.

Gender differences in serum leptin in obese people: relationships with testosterone, body fat distribution and insulin sensitivity

Testosterone levels are decreased in obese men but increased in obese women. The interplay between gonadal steroids and leptin is, at present, far from being elucidated. This study was carried out to investigate the relationship between serum leptin, plasma insulin, insulin sensitivity and free testosterone in 46 men (29 obese and 17 lean) and 65 premenopausal women (42 obese and 23 lean). In all subjects, anthropometric parameters and serum levels of insulin, leptin, free testosterone (T), dehydroepiandrosterone sulphate and sex hormone-binding globulin were measured. An oral glucose tolerance test (OGTT) and an insulin tolerance test were also performed to determine the insulin sensitivity index. Our results show a significant difference in serum leptin between lean and obese men (3.19 +/- 0.71 vs. 20.28 +/- 0.26 ng mL-1; P < 0.0005) as well as between lean and obese women (10.78 +/- 2.14 vs. 34.79 +/- 2.26 ng mL-1; P < 0.00001). Basal T concentration in the obese men was significantly lower than in the control group (18.6 +/- 1.3 vs. 23.3 +/- 1.4 ng L-1; P < 0.01), whereas in the obese women it was significantly higher than in the control group (2.0 +/- 0.2 vs. 1.3 +/- 0.1 ng L-1; P < 0.05). When multiple linear regression was performed without body mass index (BMI) in the statistical model, leptin was correlated with basal insulin (P < 0.0001), insulin sensitivity (P < 0.0001) and T (P < 0.0001) in both men and women. When BMI was included in the model as an independent variable, leptin was significantly correlated only with BMI (P < 0.0001), the degree of insulin resistance (P < 0.05) and T (only in men, P < 0.05). This study confirms that serum leptin is strongly correlated with the degree of obesity and female sex. The negative correlation between leptin and T in men, independent of BMI, is consistent with the hypothesis that T may possess an inhibitory effect on adipocyte ob gene transcription.

Lower androgenicity is associated with higher plasma levels of prothrombotic factors irrespective of age, obesity, body fat distribution, and related metabolic parameters in men

The purpose of this study was to examine the relationships between androgenic status and plasma levels of both prothrombotic and antithrombotic factors in men, irrespective of obesity, body fat distribution, and metabolic parameters. Sixty-four apparently healthy men, 40 with a body mass index (BMI) greater than 25 kg/m2 (overweight and obese [OO]) and 24 non-obese controls with a BMI less than 25, were selected and evaluated for (1) plasma concentrations of plasminogen activator inhibitor-1 (PAI-1) antigen, PAI-1 activity, fibrinogen, von Willebrand factor (vWF) antigen, vWF activity, and factor VII (FVII) as the prothrombotic factors; (2) plasma levels of tissue plasminogen activator (TPA) antigen, protein C, and antithrombin III as the antithrombotic factors; (3) fasting plasma concentrations of insulin and glucose and the lipid pattern (triglycerides [TG] and total and high-density lipoprotein [HDL] cholesterol) as the metabolic parameters; and (4) free testosterone (FT), dehydroepiandrosterone sulfate (DHEAS), and sex hormone-binding globulin (SHBG) serum levels as the parameters of androgenicity. Body fat distribution was evaluated by the waist to hip ratio (WHR). In OO and non-obese subjects taken together, plasma levels of PAI-1 antigen, fibrinogen, and FVII were inversely associated with FT (r = .255, P < .05, r = -3.14, P < .05, and r = -.278, P < .05, respectively), and the negative relationships of both fibrinogen and FVII with FT were maintained after stepwise multiple regression analysis. Plasma concentrations of PAI-1 antigen and PAI-1 activity were also negatively correlated with SHBG (r = -.315, P < .05 and r = -.362, P < .01, respectively), and these associations held irrespective of the other parameters investigated. None of the antithrombotic and fibrinolytic factors were independently related to serum androgen levels. Subjects with a BMI higher than 25 kg/m2 had higher plasma concentrations of PAI-1 antigen, PAI-1 activity, and fibrinogen as compared with non-obese controls (P < .001, P < .001, and P < .01, respectively). In addition, in OO and control subjects as a whole, multiple stepwise regression analysis showed that the associations of BMI with PAI-1 activity, fibrinogen, vWF antigen, and vWF activity were independent of any other metabolic and hormonal parameters. Plasma concentrations of PAI-1 antigen, PAI-1 activity, and fibrinogen were also directly correlated with WHR in all subjects taken together, irrespective of the other parameters investigated. Evaluation of antithrombotic factors showed that OO subjects had higher TPA plasma concentrations than non-obese controls (P < .001), whereas protein C and antithrombin III did not differ in the two groups. TPA was also directly correlated with BMI (r = .415, P < .001) and WHR (r = .393, P < .001) in all subjects. The results of this study indicate that (1) men with lower FT serum levels have higher fibrinogen and FVII plasma concentrations, and those with lower SHBG serum levels also have higher levels of PAI-1 antigen and activity; (2) irrespective of other factors, obesity per se may account for higher concentrations of PAI-1, fibrinogen, and vWF; (3) plasma levels of PAI-1 (antigen and activity) and fibrinogen correlate independently with WHR; and (4) among the investigated antithrombotic factors (TPA antigen, protein C, antithrombin III), only TPA antigen plasma concentrations are higher in men with abdominal obesity. Thus, because of the increase in several prothrombotic factors, men with central obesity, particularly those with lower androgenicity, seem to be at greater risk for coronary heart disease (CHD). Apparently, this risk is not counteracted by a parallel increase in plasma concentrations of antithrombotic factors.

Increase in both pro-thrombotic and anti-thrombotic factors in obese premenopausal women: relationship with body fat distribution

OBJECTIVES

To examine the relationship of obesity, body fat distribution, and fasting plasma insulin concentrations with the plasma levels of both pro-thrombotic and anti-thrombotic factors in premenopausal women.

SUBJECTS

32 obese women with BMI > 28 and 33 age-matched non-obese = women with BMI < 25.

MEASUREMENTS

(i) plasma concentrations of plasminogen activator inhibitor-1 antigen (PAI-1 Ag), plasminogen activator inhibitor-1 activity (PAI-1 activity), fibrinogen, von Willebrand factor antigen (vWF Ag), von Willebrand factor activity (vWF activity), and factor VII activity as pro-thrombotic factors; (ii) plasma concentrations of tissue plasminogen activator antigen (t-PA Ag), protein C, and antithrombin III as anti-thrombotic factors; (iii) fasting plasma insulin and glucose concentrations, and the lipid pattern (triglycerides, total and HDL-cholesterol) as metabolic parameters. The body fat distribution was evaluated by measuring the waist circumference and the waist-to-hip ratio (WHR).

RESULTS

Obese subjects had higher plasma concentrations of all pro-thrombotic factors as compared to non-obese controls (PAI-1 Ag, P < 0.001; PAI-1 activity, P < 0.05; fibrinogen, P < 0.001; vWF Ag, P < 0.001; vWF activity, P < 0.05; factor VII, P < 0.05). The plasma concentrations of PAI-1 Ag and vWF Ag were directly correlated with the waist circumference independently of other metabolic and non-metabolic variables (P < 0.05). Obese women were also characterized by higher plasma concentrations of anti-thrombotic factors such as t-PA Ag and protein C as compared to non-obese controls (P < 0.001 and P < 0.001, respectively), although these factors were not independently correlated with the waist circumference or the WHR.

CONCLUSION

Plasma concentrations of the pro-thrombotic factors are increased in obese women as compared to non-obese controls, and plasma levels of PAI-1 Ag and vWF Ag correlate with central fat accumulation specifically. Plasma concentrations of anti-thrombotic factors (namely protein C and t-PA Ag) are also raised in obese women, but they are not correlated with parameters of body fat distribution. The increase in protein C levels may represent a protective response partly counteracting the increase in pro-thrombotic factors in these individuals.

Interrelationships between weight loss, body fat distribution and sex hormones in pre- and postmenopausal obese women

OBJECTIVES

Relationships between regional body fat distribution and sex hormones as well as changes in sex hormones after weight loss were evaluated.

SETTING

All subjects were hospitalized in the Institute of Internal Medicine of the University of Verona.

SUBJECTS

Twenty-six premenopausal (age 33.7 +/- 10.2 years) and 15 postmenopausal (age 57.9 +/- 5.9 years) obese women.

INTERVENTIONS

Body weight, body-mass index, waist and hip circumferences, visceral fat by computed tomography and sex hormones were evaluated before and after 4 weeks on a very low energy diet.

RESULTS

Body-mass index was higher in pre-than in postmenopausal women, although the difference was not significant. Total and free testosterone were significantly higher in the pre- than in the postmenopausal group (P < 0.001). Significant negative correlations were found between age and total testosterone (r = -0.65; P < 0.001), free testosterone (r = -0.54; P < 0.001), androstenedione (r = -0.46; P < 0.01) and urinary cortisol excretion (r = -0.50; P < 0.01). A negative correlation was found between visceral fat and total testosterone (r = -0.41; P < 0.01). After adjusting for age, the negative correlation between total testosterone and visceral fat encountered both in the subject group as a whole and in premenopausal women was no longer significant, whilst a significant negative association between visceral fat and sex hormone binding globulin (SHBG) (r = -0.56; P < 0.001) was always found. When step-down regression analysis was used to evaluate the joint effect of age, menopausal status, and anthropometric and metabolic variables on sex hormones, age was the most powerful independent variable for predicting total testosterone, free testosterone and androstenedione levels, whilst menopausal status was the most powerful predictor of FSH and LH levels. Changes in hormones after VLED were analysed separately in pre- and postmenopausal women. None of the hormones changed significantly after VLED in the postmenopausal group, except for FSH values. LH, free testosterone and urinary cortisol excretion values decreased significantly after VLED in the premenopausal group.

CONCLUSIONS

Our data show that age, to a greater extent than visceral fat, seems to be negatively associated with steroid sex hormones. Weight loss seems to be associated with changes in sex hormones only in premenopausal women.