Domenico Cozzolino

Low frequency of melanocortin-4 receptor (MC4R) mutations in a Mediterranean population with early-onset obesity.

Background: Melanocortin-4 receptor (MC4R) mutations have been reported as the most common single genetic cause of obesity in some populations and it has been suggested that they may be responsible for more than 4% of early-onset obesity.Objectives: To verify the presence of mutations of the MC4R coding region in children from southern Italy with early-onset obesity.Subjects and Methods: Two-hundred and eight unrelated obese children and adolescents were included in the study. The average age at obesity onset was 4.5±2.6 y. MC4R coding region was screened using both single-strand conformation polymorphism (SSCP) analysis and denaturing high-performance liquid chromatography (DHPLC). Automatic sequencing of PCR products of all individuals that showed an aberrant SSCP and/or DHPLC pattern was performed.Results: One novel missense mutation and one previously described polymorphism (Vall03Ile) were identified. The missense mutation C142T, resulting in the substitution of proline with serine at codon 48, within the first MC4R transmembrane domain, was detected at the heterozygous state in a 15-y-old obese girl (body mass index (BMI)=35 kg/m2) who has been obese since she was 8 y old. The mutation co-segregated with the obesity phenotype for over three generations and was not found in the control population.Conclusions: Our data show MC4R obesity causing mutations in less than 0.5% of the patients (ie 1 out of 208 patients) and therefore indicate a low prevalence of MC4R variants in the obese population from southern Italy. The specific genetic background of the Mediterranean population could make it difficult for MC4R mutations to produce an essentially polygenic trait such as common obesity, at least during childhood.

Dipeptidyl peptidase-4 inhibitors and HbA1c target of <7% in type 2 diabetes: meta-analysis of randomized controlled trials

Aim: We assessed the efficacy of dipeptidyl peptidase‐4 (DPP‐4) inhibitors vildagliptin, sitagliptin, saxagliptin and alogliptin to reach the haemoglobin HbA1c target of <7% in people with type 2 diabetes.

Effects of insulin-glucose infusion on left ventricular function at rest and during dynamic exercise in healthy subjects and noninsulin dependent diabetic patients: a radionuclide ventriculographic study.

OBJECTIVES The aim of this study was to evaluate: 1) the effects of insulin administration on left ventricular ejection fraction (LVEF) during exercise, and 2) the eventual impairment of the cardiovascular response to insulin in noninsulin dependent diabetes mellitus. BACKGROUND Insulin influences the cardiovascular system, but its effect on left ventricular function has yet to be established. METHODS The effects of normal saline (test A) and insulin-glucose (insulin = 1.7 mU x kg(-1) x min(-1); glucose = 6 mg x kg(-1)min(-1)) (test B) infusions on systolic and diastolic functions at rest and during dynamic exercise were examined by radionuclide ventriculography. Twenty-two noninsulin-dependent diabetic patients and 22 gender, age and body mass index matched healthy subjects were investigated. RESULTS Both groups had normal scintigraphic parameters at rest and during dynamic exercise. Rest- and stress-LVEF as well as rest- and stress-peak filling rate were significantly (p < 0.001) lower in diabetic than in healthy subjects, both in test A and B. Rest-LVEF was significantly higher during test B than it was in test A only in diabetic subjects (p < 0.01). Stress-LVEF was significantly higher (p < 0.05) during test B than it was in test A, in both groups. Insulin-glucose infusion did not modify rest- and stress-peak filling rate in either group. No difference in left ventricular end diastolic volume and in mean blood pressure was found between test A and B at rest and during exercise in either group. A significant linear correlation between LVEF and the index of insulin sensitivity was found in diabetic patients. CONCLUSIONS In both normal and diabetic humans, insulin induces a very important rise in LVEF after submaximal work. However, the rise is significantly lower in diabetic than in nondiabetic subjects. The increase in exercise-LVEF on insulin is likely due to an enhancement of ventricular contractility. Insulin resistance could justify the lower angioscintigraphic indexes in diabetic subjects.

Tolrestat for mild diabetic neuropathy: A 52-week, randomized, placebo-controlled trial

Diabetes mellitus causes widespread damage of the peripheral nervous system, involving chiefly the somatic sensory and autonomic nervous systems. Numerous attempts to halt the decrease in nerve function through improvement of diabetic control have resulted in limited benefits, and it therefore remains unclear whether or not strict control of hyperglycemia can prevent the occurrence and progression of polyneuropathy [1]. The increased conversion of glucose to sorbitol that occurs through the polyol pathway in the hyperglycemic state has been suggested to play an important role in the pathogenesis of diabetic neuropathy [2]. Reported benefits with aldose-reductase inhibitors, which act by interrupting the accumulation of sorbitol, have been disappointing [3-7]. These discouraging results may have occurred because patients with severe degrees of polyneuropathy, in whom a decrease of nerve function is likely to be too advanced, were investigated. To determine whether treatment for mild neuropathy results in benefit, we conducted a randomized, placebo-controlled, double-blind trial of the aldose-reductase inhibitor tolrestat (Alredase, Wyeth-Ayerst) in patients with asymptomatic diabetic autonomic neuropathy. Tolrestat significantly improved autonomic nerve function and peripheral neuropathy, when present. No important side effects were observed. Methods Patients All diabetic patients participating in this study were referred from the outpatient department of the Institute of General Medicine at the University of Naples, Italy and gave written, informed consent. The study, which began in early 1990, was carried out in accordance with the Helsinki Declaration II and was approved by the ethics committee of our institution. Men and postmenopausal women were included in the study if they had noninsulin-dependent diabetes mellitus with a known duration of disease of at least 1 year, stable diabetes (no change of therapy or stable glycated hemoglobin values during the previous six months), and asymptomatic diabetic autonomic neuropathy defined by the presence of at least one pathologic cardiovascular reflex test result. Patients with other possible causes of neuropathy, including liver and renal disease, thyroid hypofunction, low cobalamine levels, malignant disease, or excessive alcohol intake, were excluded. We also excluded patients affected by diseases known to interfere with cardiovascular reflexes (ischemic heart disease, heart failure, valvular heart disease, and major cardiac arrhythmias), as well as those receiving cardiac glycosides, anticholinergics, sympathomimetics, -blockers, or other drugs affecting heart-rate variability. Eligibility criteria were investigated during a 2-week period. Study Design A randomized, double-blind, parallel-group design was used. All patients were given placebo during a 4-week run-in period (single-blind). At the end of this period, baseline neurologic functions were measured, and patients were randomly assigned either to continue to receive placebo or to receive treatment with tolrestat (200 mg/d given in the morning). Patient compliance was assessed by counting of returned tablets; 85% of pills were taken in both patient groups. During the study, patients continued their standard antidiabetic therapy, diet, oral tablets, or insulin. Change of dosage was avoided during the study to prevent varying diabetic control from influencing nerve function [8]. No treatment for peripheral neuropathy, if present, was permitted except for occasional nonnarcotic analgesic drugs given as needed. Procedures All tests assessing autonomic and peripheral neuropathy were done by persons blinded to patient treatment regimen. Autonomic Neuropathy Autonomic nervous function was measured using four cardiovascular reflex tests, each done 3 hours after patients ate lunch: heart rate response to six forced respirations in 1 minute (deep breathing, maximum/minimum heart rate expressed by the expiration/inspiration ratio between the mean of the three longest R-R intervals in expiration and the mean of the three shortest R-R intervals in inspiration), heart rate response to standing (modified 30:15 ratio; ratio of the 30th to the 15th R-R interval after changing from supine to upright position), heart rate response to a standardized Valsalva maneuver (ratio of the longest R-R interval after the maneuver to the shortest interval during the maneuver), and blood pressure change after standing (change in systolic blood pressure beginning 30 seconds after assuming the upright posture) [9, 10]. Heart rate was recorded continuously with a Lifepak 6 (PhysioSystem, Milan, Italy) recorder. Each value was calculated as the mean of at least two consecutive tests that were done in the same sequence with a few minutes rest between each test. Results from each of these tests are known to worsen with age; reference values for a nondiabetic sample were used [11]. Peripheral Neuropathy The involvement, if any, of peripheral nerves was assessed by measuring vibration perception thresholds at four sites using a biothesiometer (Biomedical Instrument Company, Newborn, Ohio). The sites studied were the right and left medial malleoli and the right and left halluces. The presence of peripheral neuropathy was defined by vibration perception threshold values of more than two standard deviations above the age-related normal range at two or more sites [12]. Clinical Assessment A questionnaire was completed on symptoms of peripheral neuropathy if present. Patients were asked to grade the severity of neuropathic symptoms of either pain (burning, deep ache, tenderness) or paresthesiae (pins and needles, asleep feelings) using a visual analog scale graded from 0 to 10, in which 0 corresponded to the absence of symptoms, and 10 corresponded to very severe symptoms. Follow-up The study was conducted on an outpatient basis with visits at 1-month intervals. Clinical assessments described previously were repeated at 6, 9, and 12 months. Results of hemoglobin, full blood count, urea and electrolytes, liver function, creatinine, urinalysis, fasting and postprandial glucose, and glycated hemoglobin (HbA1c) tests were assessed each month. The diurnal plasma glucose profile represents the mean of the plasma glucose values measured every 2 hours during the day and every 4 hours during the night. Plasma glucose was measured using a glucose-oxidase method on a Beckman glucose analyzer. Glycated hemoglobin was measured by column chromatography (Auto A1c Analyzer, Kogaku Kioto, Menarini Diagnostici, Italy); normal values for our laboratory are 4.5% to 5.7%. Statistical Analysis All data are presented as mean SD; 95% confidence intervals (CIs) are provided where appropriate. Statistically significant differences in the vibration perception threshold at each site have been reported. Although the treatment by site interaction was not statistically significant for vibration perception thresholds (repeated measures analysis of variance), we decided to not use the mean value for the four sites; the values of the two different sites of the dominant leg are reported and used for analysis. Statistical significance was assessed by paired, two-tailed t-tests within groups (that is, for differences between baseline and follow-up measures in the tolrestat and the placebo groups) and the two-tailed test for a putative treatment effect (that is, comparison of the differences between baseline and follow-up values in the tolrestat and placebo groups). Results Of the fifty patients who entered the study, five dropped out: two for intercurrent disease apparently unrelated to the study drug (one in the tolrestat group and one in the placebo group), two for unstable diabetes (one in each group), and one in the tolrestat group for adverse reactions (nausea and diarrhea) that resolved rapidly after withdrawal of the study drug. Skin rashes, dizziness, and weight gain were not detected or reported by patients during treatment. Four of these five patients dropped out before randomization and the remaining patient, after randomization. Analysis of the results (both as randomized and as treated) did not differ whether the analysis was done according to intention to treat or according to actual treatment. Forty-five patients (25 in the tolrestat group and 20 in the placebo group) completed the trial. Their clinical and metabolic characteristics are presented in Table 1. The two groups were similar in the number of patients, duration of diabetes, and metabolic control. Table 1. Characteristics of Diabetic Patients Assigned to Tolrestat Therapy or Placebo* The baseline values of HbA1c were 8.2 1.1 (mean SD) in the tolrestat group and 8.4 1.1 in the placebo group (P = 0.2). Glycemic control remained stable during the study period (repeated measures analysis of variance) in both groups: at 12 months, changes in daily glycemic profile were 0.4 (CI, 0.1 to 0.7) in the tolrestat group and 0.1 (CI, 0.3 to 0.5) in the placebo group (P = 0.1). Both groups had comparable values of cardiovascular reflex tests in the basal state. Patients treated with tolrestat showed an improvement of all tests, which appeared to begin after 6 months of treatment and persisted until the end of the study (Table 2). In this group, deep breathing increased by 0.026 expiration/inspiration ratio (95% CI, 0.015 to 0.036, P = 0.001) from baseline to 12 months. In the placebo group, the same test decreased by a value of 0.012 expiration/inspiration ratio (95% CI, 0.024 to 0.004, P = 0.03). Table 2. Nerve Function at Randomization (Basal) and throughout the Study in the Tolrestat (n = 25) and Placebo (n = 20) Groups* Figure 1 shows the changes observed at the end of the study in the tolrestat and placebo groups, respectively. If one looks at the results of the deep breathing test, 20 patients improved, 3 deteriorated, and 2 remained unchanged compared with 4, 14, and 2 patients in the placebo group. Similar results wer

Hyperlipidemia and Sexual Function in Premenopausal Women

INTRODUCTION No reported studies exist assessing the relationship between sexual function and hyperlipidemia in women. AIM In this study, we assessed the domains of sexual function in a representative sample of sexually active premenopausal women with hyperlipidemia, but without cardiovascular disease, as compared with an age-matched female population without hyperlipidemia. METHODS To be enrolled in the study, women had to meet at least one of the following criteria for the diagnosis of hyperlipidemia: low-density lipoprotein (LDL) cholesterol levels >160 mg/dL; high-density lipoprotein (HDL) cholesterol levels <50 mg/dL; or triglyceride levels >150 mg/dL. Lipid parameters were assessed and verified on blood taken at least twice in the hospital during the screening phase. Four hundred forty-one premenopausal women with hyperlipidemia were compared with 115 age-matched premenopausal women without hyperlipidemia. MAIN OUTCOME MEASURES We used the Female Sexual Function Index (FSFI) for assessing the key dimensions of female sexual function. RESULTS The two groups were well matched for age and smoking prevalence. Compared with women of the control group, women with hyperlipidemia had reduced mean global FSFI score (22.8 +/- 6.8 vs. 29.4 +/- 4.9, P < 0.001). Individual analysis of the different domains showed that women with hyperlipidemia reported significantly lower arousal, orgasm, lubrication, and satisfaction scores than control women. Based on the total FSFI score, 51% of women with hyperlipidemia had scores of 26 or less, indicating sexual dysfunction, as compared with 21% of women without hyperlipidemia (P < 0.001). Based on a more conservative analysis including women under the lower quartile of the distribution of FSFI score, 32% of women with hyperlipidemia had scores of 23 or less, as compared with 9% of women without hyperlipidemia (P < 0.001). Multiple regression analysis identified age, body mass index, HDL-cholesterol and triglycerides as independent predictors of FSFI score. CONCLUSIONS Women with hyperlipidemia have significantly lower FSFI-domain scores as compared with age-matched women without hyperlipidemia. HDL cholesterol and triglyceride levels were independently associated with the FSFI score.

Early systemic sclerosis: assessment of clinical and pre-clinical organ involvement in patients with different disease features

OBJECTIVE To assess internal organ involvement in early SSc at presentation. METHODS One hundred and fifteen patients admitted to a tertiary centre because of RP, who did not present any routinely detectable scleroderma-related internal organ involvement, were investigated for ANA and videocapillaroscopy, and underwent history and physical examination to detect symptoms/signs suggestive of SSc. Patients were then subdivided into three groups: (i) early SSc, constituted by patients without clinical manifestations other than RP, but with scleroderma marker autoantibodies and/or typical capillaroscopic abnormalities; (ii) probable SSc, constituted by patients with the same autoantibody and/or capillaroscopic status as early SSc patients, but with any of the following manifestations: digital ulcers/scars, puffy fingers, arthritis, telangiectasia, dysphagia/heartburn, shortness of breath; (iii) UCTD, constituted by patients with a specific (i.e. disease antibody marker) ANA and capillaroscopic findings plus any disease manifestation. All patients were investigated by lung functional study and B-mode echo-Doppler-cardiography. Patients who consented underwent oesophageal manometry. RESULTS An inverted mitral E : A ratio (i.e. early scleroderma cardiac involvement) and/or a diffusing lung capacity for CO <80% of the predictive value (i.e. early lung involvement) and/or basal low oesophageal sphincter pressure <15 mmHg (i.e. early oesophageal involvement) were detected in 37/51 probable SSc patients (72%), 8/19 early SSc patients (42%) and 12/45 UCTD patients (27%). CONCLUSION A scleroderma-related internal organ involvement was detected in patients from each group and, more importantly, was pre-clinical in a number of cases.

A nomogram to estimate the HbA1c response to different DPP-4 inhibitors in type 2 diabetes: a systematic review and meta-analysis of 98 trials with 24 163 patients

Objectives To develop a nomogram for estimating the glycated haemoglobin (HbA1c) response to different dipeptidyl peptidase-4 (DPP-4) inhibitors in type 2 diabetes. Design A systematic review and meta-analysis of randomised controlled trials (RCTs) of DPP-4 inhibitors (vildagliptin, sitagliptin, saxagliptin, linagliptin and alogliptin) on HbA1c were conducted. Electronic searches were carried out up to December 2013. Trials were included if they were carried out on participants with type 2 diabetes, lasted at least 12 weeks, included at least 30 participants and had a final assessment of HbA1c. A random effect model was used to pool data. A nomogram was used to represent results of the metaregression model. Participants Adults with type 2 diabetes. Interventions Any DPP-4 inhibitor (vildagliptin, sitagliptin, saxagliptin, linagliptin or alogliptin). Outcome measures The HbA1c response to each DPP-4 inhibitor within 1 year of therapy. Results We screened 928 citations and reviewed 98 articles reporting 98 RCTs with 100 arms in 24 163 participants. There were 26 arms with vildagliptin, 37 with sitagliptin, 13 with saxagliptin, 13 with linagliptin and 11 with alogliptin. For all 100 arms, the mean baseline HbA1c value was 8.05% (64 mmol/mol); the decrease of HbA1c from baseline was −0.77% (95% CI −0.82 to −0.72%), with high heterogeneity (I2=96%). Multivariable metaregression model that included baseline HbA1c, type of DPP-4 inhibitor and fasting glucose explained 58% of variance between studies, with no significant interaction between them. Other factors, including age, previous diabetes drugs and duration of treatment added low predictive power (<1%). The nomogram estimates the absolute HbA1c reduction from baseline using the type of DPP-4 inhibitor, baseline values of HbA1c and fasting glucose. Conclusions Baseline HbA1c level and fasting glucose explain most of the variance in HbA1c change in response to DPP-4 inhibitors: each increase of 1.0% units HbA1c provides a 0.4–0.5% units greater fall.

Cochlear dysfunction in type 2 diabetes: a complication independent of neuropathy and acute hyperglycemia.

The effects of type 2 diabetes on evoked otoacoustic emissions (e-OAEs) elicited by clicks in subjects with normal hearing and the involvement of the central (CNS) and peripheral nervous system and acute hyperglycemia were investigated. In study 1, 110 type 2 diabetic patients and 106 control subjects matched for age and gender were investigated by e-OAEs. Central and peripheral neuropathy were evaluated respectively by auditory brainstem responses (ABRs) and according to San Antonio Consensus Conference criteria. In study 2, 10 healthy and 10 type 2 diabetic men matched for age, all with normal e-OAEs, underwent a 5-hour hyperglycemic clamp study. e-OAE tests were performed before and during the hyperglycemic clamp. In study 1, e-OAEs were impaired in 51.8% (57 of 110) of the diabetic subjects, in comparison to 4.7% (five of 106) of the control group (P < .0001). Diabetics with impaired e-OAEs (e-OAEs-), in comparison to those with normal e-OAEs (e-OAEs+), were older (51.0+/-5.8 v 45.1+/-6.0 years, P < .001), had diabetes longer (11.5+/-4.4 v 7.0+/-3.9 years, P < .001), achieved poorer metabolic control as judged by hemoglobin A1c ([HbA1c] 6.9%+/-0.4% v 6.5%+/-0.3%, P < .001), and had more peripheral neuropathy (46% v 23%, P < .02). No difference was observed between e-OAEs- and e-OAEs+ subjects for retinopathy or nephropathy. Nevertheless, when the duration of diabetes was corrected by multiple regression analysis, the correlation between sensorineural damage and peripheral neuropathy lost significance (P = .12). Diabetic groups (e-OAEs+ and e-OAEs-) showed greater latency in waves I, III, and V and greater interwave latency for waves I to V than the control group, but there was no significant difference in ABRs between e-OAEs+ and e-OAEs- subjects. In study 2, there were no significant changes in e-OAE intensities compared with basal values during the entire hyperglycemic clamp in either type 2 diabetic or control subjects. No difference was observed between the two groups at each time of the clamp. Thus, type 2 diabetic subjects show a higher rate of compromised e-OAEs than healthy individuals. The e-OAE dysfunction does not associate with either an injury to the auditory nervous pathway or diabetic microvasculopathy. The apparent interference of peripheral neuropathy in e-OAEs loses significance when corrected for the duration of diabetes.

Effect of treatment with acarbose and insulin in patients with non‐insulin‐dependent diabetes mellitus associated with non‐alcoholic liver cirrhosis

Summary

Sensitivity to β-endorphin as a cause of human obesity

Abstract Naloxone, an opiate antagonist, was given as an intravenous bolus (5 mg) in both lean and obese healthy subjects. In lean people, there was a slight trend for insulin and C-peptide concentrations to decrease below baseline values with no glucose change. Obese subjects showed an exaggerated suppression of insulin and C-peptide and a slight decrease of glucose. Glucagon was suppressed in both groups. An infusion of human β-endorphin (0.05 mg/h) produced only minor changes in plasma glucose, insulin, glucagon, and C-peptide concentrations in lean subjects, but caused marked increments in obese. Glucagon rose in both groups, but its response was greater in obese subjects. A ten-day treatment with naloxone (1.2 mg twice a day) did not change the metabolic and hormonal responses to an oral glucose load (75 g) in lean but significantly inhibited the insulin and C-peptide responses to glucose in obese people. These results suggest that an increased opiate drive to the pancreatic beta-cell and an increased responsiveness of insulin to β-endorphin are present in human obesity.