N. Pannacciulli

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 (Σ-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.

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 (HOMAIR), as calculated by homeostatic model assessment.RESULTS: CRP was positively correlated with age, body mass index (BMI), waist, fasting glucose and insulin, HOMAIR, fat-free mass (FFM) and fat mass (FM). After multivariate analyses, age, HOMAIR, 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.

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.

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

Abstract.  Resta O, Foschino‐Barbaro MP, Bonfitto P, Giliberti T, Depalo A, Pannacciulli N, De Pergola G (Respiratory Pathophysiology, University of Bari, School of Medicine, Bari, Italy; University of Foggia, School of Medicine, Foggia, Italy; and Internal Medicine, Endocrinology, and Metabolic Diseases, University of Bari, Bari, Italy). Low sleep quality and daytime sleepiness in obese patients without obstructive sleep apnoea syndrome. J Intern Med 2003; 253: 536–543.

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-α 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.

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

OBJECTIVE: 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.

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.

Inhibitory Effect of Obesity on Gonadotropin, Estradiol, and Inhibin B Levels in Fertile Women

Objective: To examine whether obesity and insulin resistance have an independent effect on the gonadotropin, estradiol, and inhibin B serum levels and follicle count in the early follicular phase of fertile women with a wide range of BMI and without signs of hyperandrogenism.

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 (HOMAIR); 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.

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.