Alessandro Ciresi

Higher doses of cabergoline further improve metabolic parameters in patients with prolactinoma regardless of the degree of reduction in prolactin levels

Currently available studies that fully analyse the metabolic parameters in patients with prolactinoma are scarce and discordant. The aim of this study was to evaluate the metabolic effects of cabergoline (CAB) treatment in patients with newly diagnosed prolactinoma in relation to disease control and CAB dosage.

Visceral adiposity index is associated with insulin sensitivity and adipocytokine levels in newly diagnosed acromegalic patients.

CONTEXT The visceral adiposity index (VAI) has proved to be a marker of visceral adipose dysfunction, strongly associated with insulin sensitivity in both the general and specific populations of patients at metabolic risk. OBJECTIVE The objective of the study was to test VAI as a useful tool to assess early metabolic risk in acromegaly. PATIENTS Twenty-four newly diagnosed acromegalic patients (11 women and 13 men, aged 54.9 ± 13.6 yr) were grouped into those with normal (group A, n = 13, 54.2%) and those with high VAI (group B, n = 11, 45.8%). OUTCOME MEASURES Glucose, hemoglobin A1c, nadir and area under the curve (AUC) of GH (AUC(GH)) during the oral glucose tolerance test, AUC(Cpeptide) during a mixed-meal tolerance test, M value during euglycemic-hyperinsulinemic clamp, oral dispositional index (DIo), each component of the metabolic syndrome, leptin, adiponectin, TNF-α, and IL-6. RESULTS The VAI value was positively correlated with the age of patients (ρ = 0.408; P = 0.048), tumor volume (ρ = 0.638; P = 0.001), basal GH (ρ = 0.622; P = 0.001), nadir GH (ρ = 0.534; P = 0.007), AUC(GH) (ρ = 0.603; P = 0.002), IGF-I (ρ = 0.618; P = 0.001), TNF-α (ρ = 0.512; P = 0.010), and AUC(Cpeptide) (ρ = 0.715; p<0.001) and negatively with adiponectin (ρ = -0.766; P < 0.001), M value (ρ = -0.818; P < 0.001), and DIo (ρ = -0.512; P = 0.011). Patients with high VAI showed significantly higher basal GH levels (P = 0.018), AUC(GH) (P = 0.047), IGF-I (P = 0.047), AUC(Cpeptide) (P = 0.018), lower M value (P < 0.001), DIo (P = 0.006), and adiponectin levels (P < 0.001), despite the absence of a significantly higher prevalence in the overt metabolic syndrome and glucose tolerance abnormalities. AUC(GH) proved to be the main independent factor influencing VAI. CONCLUSIONS In acromegaly, VAI appears to be associated with disease activity, adiponectin levels, and insulin sensitivity and secretion and is influenced independently by GH levels. VAI could therefore be used as an easy and useful new tool in daily clinical practice for the assessment of early metabolic risk associated with active acromegaly.

The Metabolic Profile in Active Acromegaly is Gender-Specific

CONTEXT The sexual dimorphism of the somatotroph axis has been documented, but whether the acromegaly-related metabolic alterations are gender-dependent has never been investigated. OBJECTIVE The aim of the study was to evaluate the impact of gender on the metabolic parameters in acromegaly. DESIGN We conducted a retrospective, comparative, multicenter study. PATIENTS The 307 newly diagnosed acromegalic patients included in the study were grouped by gender: 157 men (aged 48.01 ± 14.28 yr), and 150 women (aged 48.67 ± 14.95 yr; of which 77 were premenopausal and 73 postmenopausal). OUTCOME MEASUREMENTS We measured each component of the metabolic syndrome (MS), hemoglobin A1c, the areas under the curve (AUCs) of glucose and insulin during 2-h oral glucose tolerance test, basal insulin resistance using the homeostasis model assessment of the insulin resistance index, stimulated insulin sensitivity using the insulin sensitivity index, early insulin-secretion rate using the insulinogenic index, β-cell function relative to insulin sensitivity using the oral disposition index and the visceral adiposity index (VAI) as the surrogate of visceral fat function. RESULTS Women showed a higher prevalence of MS (P < 0.001), higher fasting insulin levels (P < 0.001), AUC for insulin (P = 0.002), homeostasis model assessment of the insulin resistance index (P < 0.001), and VAI (P < 0.001) and a lower insulin sensitivity index (P = 0.002) than men, whereas no difference was found in fasting glucose, AUC for glucose, hemoglobin A1c, insulinogenic index, and oral disposition index. In women, fasting glucose and fasting insulin showed a significant trend toward increase (P < 0.001) and decrease (P = 0.004), respectively, from the first to the fourth quartiles of age, whereas VAI showed a trend toward increase in both groups (P < 0.001). A significantly higher prevalence of MS (P < 0.001), increased waist circumference (P < 0.001), low high-density lipoprotein cholesterol (P < 0.001), and overt diabetes mellitus (P < 0.001) was found in postmenopausal women compared with premenopausal women, as well as with men. CONCLUSIONS The majority of metabolic features in acromegaly are gender-specific. Active acromegaly in women is strongly associated with higher visceral adiposity dysfunction, insulin resistance, and the features of MS. We suggest more accurate metabolic management in acromegalic women, especially in the postmenopausal years.

Is diabetes in Cushing's syndrome only a consequence of hypercortisolism?

OBJECTIVE Diabetes mellitus (DM) is one of the most frequent complications of Cushings syndrome (CS). The aim of this study was to define the changes in insulin sensitivity and/or secretion in relation to glucose tolerance categories in newly diagnosed CS patients. DESIGN Cross-sectional study on 140 patients with CS. METHODS A total of 113 women (80 with pituitary disease and 33 with adrenal disease, aged 41.7±15.7 years) and 27 men (19 with pituitary disease and eight with adrenal disease, aged 38.1±20.01 years) at diagnosis were divided according to glucose tolerance into normal glucose tolerance (CS/NGT), impaired fasting glucose and/or impaired glucose tolerance (CS/prediabetes), and diabetes (CS/DM) groups. RESULTS Seventy-one patients had CS/NGT (49.3%), 26 (18.5%) had CS/prediabetes and 43 (30.8%) had CS/DM. Significant increasing trends in the prevalence of family history of diabetes (P<0.001), metabolic syndrome (P<0.001), age (P<0.001) and waist circumference (P=0.043) and decreasing trends in HOMA-β (P<0.001) and oral disposition index (DIo) (P<0.002) were observed among the groups. No significant trends in fasting insulin levels, area under the curve for insulin (AUCINS), Matsuda index of insulin sensitivity (ISI-Matsuda) and visceral adiposity index were detected. CONCLUSIONS Impairment of glucose tolerance is characterized by the inability of β-cells to adequately compensate for insulin resistance through increased insulin secretion. Age, genetic predisposition and lifestyle, in combination with the duration and degree of hypercortisolism, strongly contribute to the impairment of glucose tolerance in patients with a natural history of CS. A careful phenotypic evaluation of glucose tolerance defects in patients with CS proves useful for the identification of those at a high risk of metabolic complications.

Corneainacromegalic patientsasapossible target of growth hormone action

Background: GH exerts its effects on many organs and the eye also seems to be a target site, although few authors have investigated the corneal thickness in patients with acromegaly. Aim: To perform a detailed ophthalmological evaluation in acromegalic patients, in relation to disease activity. Material and methods: Twenty-eight acromegalic patients (11 males, 17 females) and 22 voluntary healthy subjects underwent complete metabolic and ophthalmological evaluation, including retinal thickness (RT), central corneal thickness (CCT), and intraocular pressure values (IOP). Results: Significantly greater CCT values were found in all acromegalic patients in comparison with controls (567 vs 528.5 μm; p<0.001), without concomitant greater corrected IOP. No difference was found for RT. Analyzing these data according to disease activity, uncontrolled patients showed greater CCT values (573.5 vs 559 μm; p=0.002) and corrected IOP (17.4 vs 16 mmHg; p=0.001) than the controlled ones. CCT also correlated with basal and nadir GH after oral glucose load levels, IGF-I levels, and duration of active disease. Conclusions: Acromegaly is characterized by greater CCT values, supporting the hypothesis that GH excess may have stimulatory effects on the cornea as well as on other target organs. Higher GH levels, disease control status and duration of active disease seem to be the main causes of increased corneal thickness. We suggest a careful and detailed corneal evaluation in acromegalic patients to prevent the potential risk of increased IOP, in addition to the already-known complications.

Glycometabolic control in acromegalic patients with diabetes: A study of the effects of different treatments for growth hormone excess and for hyperglycemia

Background: Diabetes mellitus is frequently observed in patients with acromegaly. Current therapies for acromegaly may impact glucose regulation, influencing insulin sensitivity and secretion. The question whether these therapies modify control and progression of diabetes once present is still open. Aim: Aim of our study is to analyze glucose control in acromegalic patients with diabetes, evaluating the relation with treatments for GH excess and for diabetes. Methods: Seventy patients with acromegaly and diabetes were studied. Duration and treatments of acromegaly and diabetes were recorded, together with clinical and metabolic parameters. Results: Most patients (92.8%) were treated with somatostatin analogs (SSA), either alone or in combination with dopamine-agonists (20%) or pegvisomant (15.7%); 7.1% of patients had been treated by surgery alone. Metformin (65.7%), alone or in combination with other hypoglycemic drugs, was the most frequent treatment for diabetes, followed by insulin (21.5%). Only 15.7% were treated with diet alone. The whole cohort showed a very good control of diabetes and acromegaly. Median glycated hemoglobin was 6.4% (5.9–7). IGF-I was within normal range for age in most patients. No relation was observed between duration of acromegaly or diabetes and metabolic control. SSA had a negative effect on insulin secretion, but these effects did not influence glucose control. Finally, we observed a low prevalence of nephropathy (6%) and retinopathy (20%). Conclusions: Our study shows that a good control of hyperglycemia can be obtained with success in the majority of acromegalic patients with diabetes, independently of the type of treatment for GH excess.

Predictors of microvascular complications in type 1 diabetic patients at onset: The role of metabolic memory

BACKGROUND Several epidemiological studies showed a close association between metabolic control and microvascular complications in type 1 Diabetes Mellitus (T1DM). The aim of our longitudinal observational study was to evaluate the predictive role of the main clinical and biochemical parameters in determining microvascular complications. METHODS 376 T1DM patients, hospitalized in our division from 1991 to 2005 (mean follow-up=10.93±4.26 years) were studied. Stepwise Cox regression analysis was used to identify the influence of residual ß-cell function, ß-cell autoimmunity, HbA1c levels and other clinical and laboratory parameters in the development of microalbuminuria and retinopathy. RESULTS The probability of developing microalbuminuria was higher in males than in females (HR 1.82; 95% CI 1.01-3.28; p=0.044), in patients with higher mean HbA1c values (HR 2.80; 95% CI 1.63-4.83; p<0.001), longer duration of disease (HR 1.98; 95% CI 1.10-3.57; p=0.022) and younger age of diabetes onset (HR 0.53; 95% CI 0.03-0.92; p=0.026). An increased probability of developing retinopathy was found in patients with higher mean HbA1c levels during follow-up (HR 2.35; 95% CI 1.34-4.12, p=0.003), as well as at onset (HR 1.85; 95% CI 1.06-3.24; p=0.030). CONCLUSIONS Our study suggests that among the clinical, metabolic, immunological and biochemical factors evaluated at onset, only HbA1c is predictive for the microangiopathy development in T1DM.

No phenotypic differences for polycystic ovary syndrome (PCOS) between women with and without type 1 diabetes mellitus.

CONTEXT Women with type 1 diabetes mellitus (DM1) have a higher prevalence of polycystic ovary syndrome (PCOS) than the general population. OBJECTIVE The aim of this study was to clarify, in DM1 women with PCOS (PCOS-DM1), the influence of insulin therapy and glycemic control and evaluate the hormonal and phenotypic differences with age-matched and body mass index (BMI)-matched women with PCOS without diabetes. DESIGN, SETTING, AND PATIENTS We evaluated 103 DM1 women with and without PCOS treated with intensive insulin therapy; 38 age-matched and BMI-matched women with PCOS without diabetes were compared in a cross-sectional study. OUTCOME MEASUREMENTS Clinical, anthropometric, and metabolic parameters were evaluated. Hormonal evaluation and ovary ultrasound were performed during the follicular phase of the menstrual cycle. RESULTS Applying the diagnostic criteria of the Androgen Excess Society, 38 (36.89%) women with DM1 showed PCOS. The 38 PCOS-DM1 women showed no differences in treatment and glycemic control compared with DM1 women without PCOS. The only difference was a higher visceral adiposity index in PCOS-DM1 (1.21±0.70 vs 0.90±0.32; P=.002). PCOS-DM1 showed no phenotypic differences with age-matched and BMI-matched PCOS without diabetes. The hormonal pattern was similar except that higher levels of Δ4androstenedione were found in PCOS-DM1 (12.89±3.49 vs 2.79±1.75 nmol/L; P=.010). CONCLUSIONS The women with PCOS-DM1 do not exhibit particular phenotypic characteristics compared with nondiabetic women with PCOS. However, this pathological disorder must not be underestimated because it could be an additional cardiovascular risk factor in women with DM1.

Serum visfatin levels in acromegaly: Correlation with disease activity and metabolic alterations

OBJECTIVE The studies that have extensively evaluated the relation between adipokines and metabolic parameters in acromegaly treatment are quite discordant. We aimed to evaluate and correlate a set of selected adipokines, known to have a metabolic role, with the disease activity, metabolic status and treatment modalities. DESIGN Data of 56 consecutive acromegalic patients (31 M and 25 F; aged 54 ± 12 years), admitted to the section of Endocrinology of the University of Palermo during the years 2005-2014, including 16 newly diagnosed untreated (ND), 21 during therapy with somatostatin analogues (SA), 12 with pegvisomant (PE) and 7 after surgical treatment (SU), grouped into uncontrolled (group A: No. 33) and controlled (group B: No. 23) were evaluated. Anthropometric and metabolic parameters, insulin sensitivity indexes, visceral adiposity index (VAI), leptin, soluble leptin receptor, adiponectin, visfatin, resistin, adipsin and non-esterified fatty acids (NEFAs) were assessed. In a subgroup of 21 subjects, the insulin sensitivity index (M value) derived from euglycemic clamp was calculated. RESULTS Group A showed higher Homa-IR (p < 0.001), VAI (p < 0.001), triglycerides (p < 0.001), visfatin (p < 0.001), and NEFAs (p < 0.001) and lower ISI Matsuda (p < 0.001), M value (p < 0.001), HDL cholesterol (p < 0.001) and leptin (p < 0.001) than group B. ND patients showed higher VAI, triglycerides, Homa-IR, and visfatin and lower ISI Matsuda, M-value, and leptin compared to other groups (all p < 0.050), while no differences were found among SA, PE and SU patients. IGF-1 (p = 0.048), M-value (p = 0.0029) and VAI (p = 0.010) were independently associated with visfatin, while only ISI Matsuda (p = 0.019) was associated with leptin. CONCLUSIONS In acromegaly visfatin could be considered a useful index of disease activity and metabolic alterations, such as insulin resistance and adipose dysfunction, regardless of the type of treatment.

Utility of C-peptide for a reliable estimate of insulin secretion in children with growth hormone deficiency.

OBJECTIVE GH treatment (GHT) can lead to glucose metabolism impairment through decreased insulin sensitivity and impaired pancreatic β-cell function, which are the two key components of the pathogenesis of diabetes. Therefore, in addition to insulin sensitivity, during GHT it is very important to perform a reliable evaluation of insulin secretion. However, conflicting data exist regarding the insulin secretion in children during GHT. C-peptide provides a more reliable estimate of β-cell function than insulin, but few studies evaluated it during GHT. Our aim was to assess the usefulness of C-peptide in the evaluation of insulin secretion in GH deficiency (GHD) children. DESIGN In 48 GHD children, at baseline and after 12 and 24months of GHT, and in 56 healthy subjects we evaluated fasting and glucagon-stimulated (AUCCpep) C-peptide levels in addition to other commonly used secretion indexes, such as fasting and oral glucose tolerance test-stimulated insulin levels (AUCINS), Homa-β, and insulinogenic index. The main outcomes were the change in C-peptide during GHT and its correlation with the auxological and hormonal parameters. RESULTS At baseline GHD children showed a significant lower AUCCpep (p=0.006), while no difference was found for the other indexes. Both fasting C-peptide (beta 0.307, p=0.016) and AUCCpep (beta 0.379, p=0.002) were independently correlated with IGF-I SDS, while no correlation was found for all other indexes. After 12months an increase in Homa-β (p<0.001), fasting C-peptide (p=0.002) and AUCCpep (p<0.001) was found. At multivariate analysis, only fasting C-peptide (beta 0.783, p=0.001) and AUCCpep (beta 0.880, p<0.001) were independently correlated with IGF-I SDS. CONCLUSIONS C-peptide, rather than the insulin-derived indexes, has proved to be the most useful marker of insulin secretion correlated to IGF-I levels in GHD children. Therefore, we suggest the use of glucagon test both as diagnostic test for the GH assessment and as a useful tool for the evaluation of insulin secretion during GHT in children.