Insulin Resistance Is Associated with Intraocular Pressure Elevation in a Non-Obese Korean Population

Based on reports of an association between elevated intraocular pressure (IOP) and metabolic syndrome (MetS), and the major role of insulin resistance (IR) in MetS pathogenesis, a positive association between IOP and IR has been hypothesized. Although Asian populations tend to have lower body mass indices (BMIs) than Western populations, they tend to have a higher risk of developing MetS. This study examined the hypothesis that the association between IOP and IR differs by obesity status in an Asian population, by examining a nationally representative sample of South Korean adults. Data collected from 4,621 South Korean adults regarding demographic, lifestyle, and laboratory parameters by the 2010 Korea National Health and Nutrition Examination Survey were subjected to linear regression analysis to evaluate the relationship between IOP and metabolic profiles. After adjusting for confounding factors, the data were subjected to multiple linear regression analysis to examine the association between IR, as measured by the homeostasis model assessment of insulin resistance (HOMA-IR), and IOP. Obesity was defined as BMI≥27.5 kg/m², and the subjects were divided into obese vs. non-obese groups for investigation of the association between IR and IOP according to obesity status. IOP was found to correlate with fasting blood sugar, total cholesterol, insulin, and HOMA-IR values in non-obese men; and with BMI, waist circumference, triglycerides, total cholesterol, HOMA-IR, and low-density lipoprotein cholesterol values in non-obese women, whereas no association between IOP and IR was found in obese men or women. IOP was significantly associated with IR in non-obese men and women after adjusting for age, and in non-obese men after adjusting for age, BMI, and lifestyle and demographic factors. These findings indicate that a positive and independent relationship exists between IOP and IR in non-obese individuals only, suggesting that other factors likely contribute to IOP elevation in obese individuals.     

The Dimension of Hyoid Bone Is Independently Associated with the Severity of Obstructive Sleep Apnea

Introduction

We hypothesized that the size of the hyoid bone itself may affect the severity of sleep apnea. The aim of this study was to identify the relationship between hyoid bone dimensions and the severity of sleep apnea using computerized tomography (CT) axial images.

Methods

We retrospectively measured the hyoid bone in axial images of neck CTs and correlated these measurements with results of polysomnography in a total of 106 male patients. The new hyoid bone parameters studied in this study were as follows: distance between bilateral lesser horns (LH-d), distance between bilateral greater horns (GH-d), distance from the most anterior end of the hyoid arch to GH-d (AP), distance from the greater to the lesser horn on right and left sides (GH-LH), and the anterior angle between bilateral extensive lines from the greater to the lesser horn (H-angle). Data was analyzed using univariate and multivariate logistic regression, and Pearson correlation tests.

Results

We found a significant inverse correlation between the apnea-hypopnea index (AHI) and GH-d or AP. Neither the LH-d, GH-LH, nor H-angle were associated with the AHI. The patient group that met the criteria of both GH-d<45.4 and AP<33.4 demonstrated the most severe AHI.

Conclusion

The lateral width or antero-posterior length of hyoid bone was associated with AHI and predicted the severity of sleep apnea in male patients. This finding supports the role of expansion hyoidplasty for treatment of sleep apnea. Pre-operative consideration of these parameters may improve surgical outcomes in male patients with sleep apnea.     

Association between Plasma Neutrophil Gelatinase Associated Lipocalin Level and Obstructive Sleep Apnea or Nocturnal Intermittent Hypoxia

Background

Both obstructive sleep apnea (OSA) and a novel lipocalin, neutrophil gelatinase associated lipocalin (Ngal), have been reported to be closely linked with cardiovascular disease and loss of kidney function through chronic inflammation. However, the relationship between OSA and Ngal has never been investigated.

Objectives

To evaluate the relationship between Ngal and OSA in clinical practice.

Methods

In 102 patients, polysomnography was performed to diagnose OSA and plasma Ngal levels were measured. The correlations between Ngal levels and OSA severity and other clinical variables were evaluated. Of the 46 patients who began treatment with continuous positive airway pressure (CPAP), Ngal levels were reevaluated after three months of treatment in 25 patients.

Results

The Ngal level correlated significantly with OSA severity as determined by the apnea hypopnea index (r = 0.24, p = 0.01) and 4% oxygen desaturation index (ODI) (r = 0.26, p = 0.01). Multiple regression analysis showed that the Ngal level was associated with 4%ODI independently of other clinical variables. Compliance was good in 13 of the 25 patients who used CPAP. Although the OSA (4%ODI: 33.1±16.7 to 1.1±1.9/h, p<0.01) had significantly improved in those with good compliance, the Ngal levels were not significantly changed (60.5±18.1 before CPAP vs 64.2±13.9 ng/ml after CPAP, p = 0.27).

Conclusions

Plasma Ngal levels were positively associated with the severity of OSA. However, the contribution rate of OSA to systemic Ngal secretion was small and changes in Ngal levels appeared to be influenced largely by other confounding factors. Therefore, it does not seem reasonable to use the Ngal level as a specific biomarker of OSA in clinical practice.     

Serum Zinc Concentration Is Inversely Associated with Insulin Resistance but Not Related with Metabolic Syndrome in Nondiabetic Korean Adults

Although zinc was known to be associated with insulin metabolism and diabetes, the relationship of serum zinc concentration with insulin resistance (IR) and metabolic syndrome (MetS) was not well investigated in general population. The aim of this study is to evaluate the relationships of serum zinc concentration with IR and MetS in a nondiabetic adult population. This cross-sectional study included 656 men and 825 women who were nondiabetic adults from the fifth Korea National Health and Nutrition Examination Survey conducted in 2010. Serum zinc concentration and metabolic parameters were measured. IR was estimated by homeostatic model assessment (HOMA2). MetS was defined according to the National Cholesterol Education Program Adult Treatment Panel III criteria. Serum zinc concentration was negatively correlated with homeostasis model assessment for insulin resistance (HOMA2-IR) in men (r?=??0.104, P?=?0.008), but not in women. After adjusting for conventional cardiovascular risk factors, the inverse correlation was significant in both men and women (B?=??0.262, SE?=?0.060 for men, and B?=??0.129, SE?=?0.052 for women). However, serum zinc concentration was not different between the groups with and without MetS (P?=?0.752 for men and P?=?0.371 for women). In conclusion, serum zinc concentration was inversely associated with IR but not related to MetS in nondiabetic adult population.     

Neurodegeneration in Drop-Dead Mutant Drosophila melanogaster Is Associated with the Respiratory System but Not with Hypoxia

Mutations in the gene drop-dead (drd) cause diverse phenotypes in adult Drosophila melanogaster including early lethality, neurodegeneration, tracheal defects, gut dysfunction, reduced body mass, and female sterility. Despite the identification of the drd gene itself, the causes of early lethality and neurodegeneration in the mutant flies remain unknown. To determine the pattern of drd expression associated with the neurodegenerative phenotype, knockdown of drd with various Gal4 drivers was performed. Early adult lethality and neurodegeneration were observed upon knockdown of drd in the tracheal system with two independent insertions of the breathless-Gal4 driver and upon knockdown in the tracheal system and elsewhere with the DJ717-Gal4 driver. Surprisingly, rescue of drd expression exclusively in the tracheae in otherwise mutant flies rescued the neurodegenerative phenotype but not adult lethality. Gut dysfunction, as measured by defecation rate, was not rescued in these flies, and gut function appeared normal upon tracheal-specific knockdown of drd. Finally, the hypothesis that tracheal dysfunction in drd mutants results in hypoxia was tested. Hypoxia-sensitive reporter transgenes (LDH-Gal4 and LDH-LacZ) were placed on a drd mutant background, but enhanced expression of these reporters was not observed. In addition, manipulation of drd expression in the tracheae did not affect expression of the hypoxia-induced genes LDH, tango, and similar. Overall, these results indicate that there are at least two causes of adult lethality in drd mutants, that gut dysfunction and neurodegeneration are independent phenotypes, and that neurodegeneration is associated with tracheal expression of drd but not with hypoxia.     

Serum Bilirubin Is Inversely Associated with Increased Arterial Stiffness in Men with Pre-Hypertension but Not Normotension

Objective

Serum bilirubin level has shown to be inversely associated with coronary atherosclerosis, and may serve as a protective biomarker of coronary artery disease. Serum bilirubin has also been shown to be negatively associated with brachial-ankle pulse wave velocity (baPWV) in men without a history of hypertension, and in men with hypertension. It is unknown whether such associations can be observed in the pre-hypertensive or normotensive population. This study thus aimed to investigate the relationship between serum bilirubin level and increased arterial stiffness in subjects with pre-hypertension and normotension for both genders.

Methods

A cross-sectional sample of 3,399 apparently healthy subjects undergoing a medical check-up at National Cheng Kung University Hospital was enrolled between October 2006 and August 2009, after excluding subjects with serum total bilirubin level greater than 20.52 μmol/L. Increased arterial stiffness was defined as baPWV of 1,400 cm/s or higher as the dichotomous variable and bilirubin as the continuous variable.

Results

Based on multiple linear regression analysis, serum bilirubin level was inversely associated with baPWV in non-hypertensive men (β = -0.066, p < 0.001) but not in non-hypertensive women. In addition, the inverse relationship between bilirubin level and baPWV was found statistically significant only in pre-hypertensive men (β = -0.110, p < 0.001). Multiple logistic regression analysis showed that serum bilirubin was inversely associated with increased arterial stiffness in men with pre-hypertension (odds ratio = 0.955, 95% confidence interval = 0.916–0.996, p < 0.05) but not normotension after adjustment for other confounding factors. However, the relationship between total bilirubin level and increased arterial stiffness did not reach statistical significance for female subjects with pre-hypertension and normotension.

Conclusion

Serum bilirubin is inversely associated with increased arterial stiffness in men with pre-hypertension but not normotension. The association between bilirubin level and arterial stiffness was not found significant in women.     

Serum LBP Is Associated with Insulin Resistance in Women with PCOS

Introduction

Lipopolysaccharide-binding protein (LBP) is closely associated with many metabolic disorders. However, no study has been done to explore the relationship between LBP and polycystic ovary syndrome (PCOS). The objective of this study was to investigate whether the serum LBP level is elevated and associated with insulin resistance (IR) in PCOS.

Participants and Design

In this cross-sectional study, 117 PCOS patients and 121 age-matched controls were recruited. Hyperinsulinemic-euglycemic clamp was performed with an expression of M value for insulin sensitivity. Fasting serum samples were collected to detect LBP, lipids, insulin, sex hormones and high sensitive C reactive protein (hs-CRP). Pearson’s correlation and multiple linear regression was used to analyze the associations between M value and LBP level.

Settings

The study was performed in a clinical research center.

Results

Compared with controls, PCOS subjects had a significantly higher LBP concentration (33.03±14.59 vs. 24.35±10.31 μg/ml, p<0.001), and lower M value (8.21±3.06 vs. 12.31±1.72 mg/min/kg, p<0.001). Both in lean and overweight/obese individuals, serum LBP level was higher in PCOS subjects than that in controls. M value was negatively correlated with body mass index (BMI), fasting serum insulin, triglycerides, low-density lipoprotein cholesterol (LDL-c), free testosterone, high sensitive C reactive protein (hs-CRP) and LBP, whereas positively correlated with high-density lipoprotein cholesterol (HDL-c) and sex hormone binding globulin (SHBG). Serum LBP level was associated with M value after adjusting for BMI, fasting serum insulin, SHBG, as well as hs-CRP.

Conclusion

Serum LBP level significantly is elevated in PCOS, and is independently associated with IR in PCOS.     

Earlier Menarche Is Associated with Lower Insulin Sensitivity and Increased Adiposity in Young Adult Women

Objective

We aimed to assess whether age at menarche was associated with insulin sensitivity in young adult women.

Methods

We studied 54 healthy young women aged 20–30 years. Participants were grouped according to age at menarche: Early (≤11.0 years; n=13), Average (>12.0 and ≤13.0 years; n=28), and Late (≥14.0 years, n=13). Primary outcome was insulin sensitivity measured using intravenous glucose tolerance tests and Bergman’s minimal model. Body composition was assessed using whole-body dual-energy X-ray absorptiometry.

Results

Earlier menarche was associated with lower insulin sensitivity (p=0.015). There was also a continuous increase in adiposity with younger age at menarche, which was associated with increased weight (p=0.001), BMI (p=0.002), total body fat (p=0.049), and truncal fat (p=0.020). Stratified analyses showed that insulin sensitivity in Early women (5.5 x10^-4·min^-1(mU/l)) was lower than in Average (8.0 x10^-4·min^-1(mU/l), p=0.021) and Late (8.6 x10^-4·min^-1(mU/l), p=0.033) groups. Early women (weight=66.1 kg; BMI=24.1 kg/m²) were considerably heavier and fatter than Average (59.0 kg, p=0.004; 21.4 kg/m², p=0.002) and Late (57.0 kg, p=0.001; 20.8 kg/m², p=0.0009) women.

Conclusions

Early menarche is associated with lower insulin sensitivity and increased adiposity in young adulthood, potentially increasing the risk of type 2 diabetes and the metabolic syndrome later in life.     

Gly40Ser Polymorphism of the Glucagon Receptor Gene Is Associated with Central Adiposity in Men

Objective: To study the association between the Gly40Ser polymorphism of the glucagon receptor gene (GCG‐R) and central adiposity. Research Methods and Procedures: Data from 985 working men (The Olivetti Heart Study) examined in 1994 were used in a cross‐sectional design. A complete anthropometry was performed; body mass index and waist circumference were taken as measures of total and central adiposity, respectively. The GCG‐R Gly40Ser polymorphism was characterized. Biochemical variables linked to energy metabolism were measured. Results: The GCG‐R Gly40Ser variant was present in 37 individuals only in heterozygous form and was significantly associated with anthropometric indices of central adiposity, accounting for age and body mass (odds ratio for waist circumference > 94 cm; 95% confidence interval: 3.14, 1.26 to 7.81), whereas no difference between the two groups was found with regard to biochemical indices of insulin resistance or plasma leptin levels. Discussion: The Gly40Ser polymorphism of the GCG‐R gene is associated with central adiposity independently from total body mass in men.     

Infrequent Breakfast Consumption Is Associated with Higher Body Adiposity and Abdominal Obesity in Malaysian School-Aged Adolescents

Unhealthy dietary pattern increases the risk of obesity and metabolic disorders in growing children and adolescents. However, the way the habitual pattern of breakfast consumption influences body composition and risk of obesity in adolescents is not well defined. Thus, the aim of the present study was to assess any associations between breakfast consumption practices and body composition profiles in 236 apparently healthy adolescents aged 12 to 19 years. A self-administered questionnaire on dietary behaviour and lifestyle practices and a dietary food frequency questionnaire were used. Body composition and adiposity indices were determined using standard anthropometric measurement protocols and dual energy χ-ray absorptiometry (DXA). Mean age of the participants was 15.3±1.9 years. The majority of participants (71.2%) fell in the normal body mass index (BMI) ranges. Breakfast consumption patterns showed that only half of the participants (50%) were consuming breakfast daily. Gender-specific multivariate analyses (ANCOVA) showed that in both boys and girls, those eating breakfast at least 5 times a week had significantly lower body weight, body mass index (BMI), BMI z-scores, waist circumference, body fat mass and percent body fat (%BF) compared to infrequent breakfast eaters, after adjustment for age, household income, pubertal status, eating-out and snacking practices, daily energy intakes, and daily physical activity levels. The present findings indicate that infrequent breakfast consumption is associated with higher body adiposity and abdominal obesity. Therefore, daily breakfast consumption with healthy food choices should be encouraged in growing children and adolescents to prevent adiposity during these critical years of growth.     

A Common Variant of NGEF Is Associated with Abdominal Visceral Fat in Korean Men

Central adiposity, rather than body mass index (BMI), is a key pathophysiological feature of the development of obesity-related diseases. Although genetic studies by anthropometric measures such as waist circumference have been widely conducted, genetic studies for abdominal fat deposition measured by computed tomography (CT) have been rarely performed. A total of 1,243 participants who were recruited from two health check-up centers were included in this study. We selected four and three single-nucleotide polymorphisms (SNPs) in NGEF and RGS6, respectively, and analyzed the associations between the seven SNPs and central adiposity measured by CT using an additive, dominant, or recessive model. The participants were generally healthy middle-aged men (50.7 ± 5.3 years). In the additive model, the rs11678490 A allele of NGEF was significantly associated with total adipose tissue, visceral adipose tissue (VAT), and subcutaneous adipose tissue (all P < 0.05). The AA genotype of this SNP in the recessive model showed a more significant association with all adiposity traits, and its association with VAT remained significant even after adjustment for BMI (P = 0.005). In the overall or visceral obesity group analysis, the AA genotype of rs11678490 showed no association with overall obesity (P = 0.148), whereas it was significantly associated with visceral obesity both before (P = 0.010) and after (P = 0.029) adjustment for BMI. In particular, an AA genotype effect was conspicuous between lower and upper groups with 5% extreme VAT phenotypes (OR = 9.59, 95% CI = 1.50–61.31). However, we found no significant association between SNPs of RGS6 and central adiposity. We identified a visceral-fat-associated SNP, rs11678490 of NGEF, in Korean men. This study suggests that the genetic background of central adiposity and BMI is different, and that additional efforts should be made to find the unique genetic architecture of intra-abdominal fat accumulation.     

Increased Susceptibility to Insulin Resistance Associated with Abdominal Obesity in Aging Rats**

Objective: Recent data have suggested that the insulin resistance observed with aging may be more related to adiposity than aging per se. We asked whether the insulin resistance observed in aged rats was comparable (both in magnitude and location) to that of fat‐fed rats. Research Methods and Procedures: We performed hyperinsulinemic (5 mU/min per kg) euglycemic clamps with tracer in conscious, 6‐hour fasted young (YL), fat‐fed young (YF), fat‐fed old (OF), and calorically restricted old (OL) rats. Results: Intraabdominal fat measurements showed that OF and YF rats were more obese than YL (p ≤ 0.001; YF > OF > YL). Caloric restriction not only prevented age‐related obesity but also reduced the ratio of intraabdominal fat to lean body mass (LBM) compared with YL (OL: 0.59 ± 0.05 vs. YL: 1.07 ± 0.04; p = 0.017). Despite similar incremental insulin, YF and OF rats required 40% less infused glucose to maintain euglycemia than YL and OL rats (p < 0.001). Insulin‐stimulated glucose uptake (Si_Rd: ΔRd/(ΔInsulin × Glucose_SS) was impaired in OF rats (OF: 14.03 ± 1.79 vs. YL: 23.08 ± 1.87 × 10³ dL/min × kg LBM per pM; p = 0.004) and improved in OL rats (29.41 ± 1.84 × 10³ dL/min × kg LBM per pM; p = 0.031) compared with YL. Despite greater obesity, YF rats did not exhibit lower Si_Rd compared with OF rats (p = 0.58). In contrast, the ability of insulin to suppress endogenous glucose production (EGP; Si_EGP: ΔEGP/(ΔInsulin × Glucose_SS) was not impaired in OF rats (OF vs. YL; p = 0.61) but was markedly impaired in YF rats by ～75% (1.72 ± 0.66 × 10³ dL/min × kg per pM; p = 0.013). Surprisingly, separate regression analysis for old and young animals revealed that old rats exhibited a significantly steeper regression between Si (Rd and EGP) and adiposity than young rats (p < 0.05). Thus, older rats showed a proportionately greater decrement in insulin sensitivity with an equivalent increase in adiposity. Discussion: These data suggest that, in rodents, youth affords significant protection against obesity‐induced insulin resistance.     

K121Q PC‐1 Gene Polymorphism Is Not Associated with Insulin Resistance in a Spanish Population

Objective : To investigate the effect of the K121Q plasma cell membrane glycoprotein (PC‐1) polymorphism on the components of the insulin resistance syndrome in a population‐based nationwide multicenter study in Spain. Research Methods and Procedures : The subjects of the study were 293 nonrelated adults (44.7% men and 55.3% women) ages 35 to 64 years randomly chosen from a nationwide population‐based survey on obesity and related conditions, including insulin resistance and cardiovascular risk factors. Obesity‐related anthropometric measurements included blood pressure, oral glucose tolerance test, lipid profile (total cholesterol, high‐density lipoprotein‐ and low‐density lipoprotein‐cholesterol, and triglycerides), plasma leptin, insulin levels by radioimmunoassay, and insulin resistance (homeostasis model assessment). K121Q PC‐1 genotypes were determined by restriction fragment‐length polymorphism‐polymerase chain reaction. Results : Overall Q allele frequency was 0.14, with no differences between obese and nonobese individuals (0.15 vs. 0.13). After adjustment for sex, age, BMI, and degree of glucose tolerance, the Q allele was associated with high plasma leptin and triglyceride levels, but not with insulin resistance. Discussion : The results showed that the K121Q PC‐1 polymorphism in the Spanish population has no significant impact on insulin sensitivity.     

Tongue Volume Influences Lowest Oxygen Saturation but Not Apnea-Hypopnea Index in Obstructive Sleep Apnea

Objectives

The aim of this study was to identify correlations between sleep apnea severity and tongue volume or posterior airway space measured via three-dimensional reconstruction of volumetric computerized tomography (CT) images in patients with obstructive sleep apnea (OSA) for use in predicting OSA severity and in surgical treatment. We also assessed associations between tongue volume and Mallampati score.

Methods

Snoring/OSA male patients (n = 64) who underwent polysomnography, cephalometry, and CT scans were enrolled in this retrospective study. OSA was diagnosed when the apnea-hypopnea index (AHI) was greater than 5 (mild 5–14; moderate 15–29; severe>30). The patients were also categorized into the normal-mild group (n = 22) and the moderate-severe group (n = 42). Using volumetric CT images with the three-dimensional reconstruction technique, the volume of the tongue, posterior airway space volume, and intra-mandibular space were measured. The volumes, polysomnographic parameters, and physical examination findings were compared, and independent factors that are related to OSA were analysed.

Results

No associations between tongue volume or posterior airway space and the AHI were observed. However, multivariate linear analyses showed that tongue volume had significantly negative association with lowest O₂ saturation (r = 0.365, p = 0.027). High BMI was related to an increase in tongue volume. Modified Mallampati scores showed borderline significant positive correlations with absolute tongue volume (r = 0.251, p = 0.046) and standardized tongue volume (absolute tongue volume / intramandibular area; r = 0.266, p = 0.034). Between the normal-mild and moderate-severe groups, absolute tongue volumes were not different, although the standardized tongue volume in the moderate-severe group was significantly higher.

Conclusion

Absolute tongue volume showed stronger associations with lowest O₂ saturation during sleep than with the severity of AHI. We also found that high BMI was a relevant factor for an increase in absolute tongue volume and modified Mallampati grading was a useful physical examination to predict tongue size.     

Obstructive Sleep Apnea Is Associated with Liver Damage and Atherosclerosis in Patients with Non-Alcoholic Fatty Liver Disease

Background/Aims

We assessed whether obstructive sleep apnea (OSA) and nocturnal hypoxemia are associated with severity of liver fibrosis and carotid atherosclerosis in patients with biopsy-proven NAFLD and low prevalence of morbid obesity. Secondary aim was to explore the association of OSA and hypoxemia with NASH and severity of liver pathological changes.

Methods

Consecutive patients (n = 126) with chronically elevated ALT and NAFLD underwent STOP-BANG questionnaire to estimate OSA risk and ultrasonographic carotid assessment. In patients accepting to perform cardiorespiratory polygraphy (PG, n = 50), OSA was defined as an apnea/hypopnea index ≥5. A carotid atherosclerotic plaque was defined as a focal thickening >1.3 mm.

Results

Prevalence of high OSA risk was similar in patients refusing or accepting PG (76% vs 68%, p = 0.17). Among those accepting PG, overall OSA prevalence was significantly higher in patients with F2-F4 fibrosis compared to those without (72% vs 44%; p = 0.04). Significant fibrosis was independently associated with mean nocturnal oxygen saturation (SaO₂)<95% (OR 3.21, 95%C.I. 1.02–7.34; p = 0.04). Prevalence of OSA tended to be higher in patients with, than in those without, carotid plaques (64% vs 40%; p = 0.08). Carotid plaques were independently associated with %time at SaO2<90% >1 (OR 6.30, 95%C.I. 1.02–12.3; p = 0.01).

Conclusions

In NAFLD patients with chronically elevated ALT at low prevalence of morbid obesity, OSA was highly prevalent and indexes of SaO₂ resulted independently associated with severity of liver fibrosis and carotid atherosclerosis. These data suggest to consider sleep disordered breathing as a potential additional therapeutic target in severe NAFLD patients.     

Insulin Resistance Is an Independent Determinate of ED in Young Adult Men

Background

Insulin resistance (IR) triggers endothelial dysfunction, which contributes to erectile dysfunction (ED) and cardiovascular disease.

Aim

To evaluate whether IR was related to ED in young adult patients.

Methods

A total of 283 consecutive men complaining of ED at least six months were enrolled, with a full medical history, physical examination, and laboratory tests collected. Quantitative Insulin Sensitivity Check Index (QUICKI) was used to determine IR. The severity of ED was assessed by IIEF-5 questionnaire. Endothelial function was assessed by ultrasonographic examination of brachial artery flow mediated dilation (FMD).

Results

IR was detected in 52% patients. Subjects with IR had significant higher total cholesterol, triglycerides, low density lipoprotein-cholesterol (LDL-c), glycated haemoglobin (HBA1c), high sensitivity C-reactive protein (hs-CRP) and body mass index (BMI), but showed significant lower IIEF-5 score, FMD%, high density lipoprotein -cholesterol (HDL-c), testosterone, sex hormone binding globulin (SHBG) levels than patients without IR. Multiple regression analysis showed QUICKI and testosterone were independent predictors of IIEF-5 score. Furthermore, the incidence of IR was correlated with the severity of ED.

Conclusions

Compared with other CVFs, IR was found as the most prevalent in our subjects. Besides, IR was independently associated with ED and its severity, suggesting an adverse effect of insulin resistance on erectile function.     

Circulating Obestatin Levels Correlate with Fasting Insulin and HOMA-IR but Not with Hypertension in Elderly Men

Obestatin, encoded by the same gene as ghrelin, was first described as a physiological opponent of ghrelin. The association between circulating obestatin levels and blood pressure remains unclear. Furthermore, adequate information is non-existent regarding the older male population with hypertension. For this purpose, we enrolled 185 unrelated hypertensive male patients aged ≥80 years (range 80–102 years). One hundred seventy nine age-matched healthy subjects served as controls. Plasma levels of obestatin and insulin were measured using commercial ELISA and RIA. HOMA-IR was calculated using standard method. We found that plasma obestatin levels correlated significantly with insulin levels (P = 0.034) and homeostasis model assessment index for insulin resistance (HOMA-IR: P = 0.028). However, plasma obestatin differed non-significantly between hypertensive (5.06 ± 0.68 ng/mL) and non-hypertensive (4.72 ± 0.82 ng/mL) individuals. Plasma obestatin levels were not associated with systolic (P = 0.818) or diastolic (P = 0.564) blood pressure, waist-to-hip ratio (WHR: P = 0.725), uric acid (P = 0.603), total cholesterol (TC: P = 0.589), low-density lipoprotein cholesterol (LDL-C: P = 0.057); high-density lipoprotein cholesterol (HDL-C: P = 0.432), triglyceride (TG: P = 0.418), and fasting blood glucose (FBG: P = 0.101). We, therefore, concluded that fasting circulating obestatin levels did not directly correlate with blood pressure in men aged ≥80 years.     

Short Sleep Duration Is Associated with Risk of Future Diabetes but Not Cardiovascular Disease: a Prospective Study and Meta-Analysis

Epidemiologic studies have observed association between short sleep duration and both cardiovascular disease (CVD) and type 2 diabetes, although these results may reflect confounding by pre-existing illness. This study aimed to determine whether short sleep duration predicts future CVD or type 2 diabetes after accounting for baseline health. Baseline data for 241,949 adults were collected through the 45 and Up Study, an Australian prospective cohort study, with health outcomes identified via electronic database linkage. Cox proportional hazards models were used to estimate hazard ratios (HR) and 95% confidence intervals. Compared to 7h sleep, <6h sleep was associated with incident CVD in participants reporting ill-health at baseline (HR=1·38 [95% CI: 1·12-1·70]), but not after excluding those with baseline illness and adjusting for baseline health status (1·03 [0·88-1·21]). In contrast, the risk of incident type 2 diabetes was significantly increased in those with <6h versus 7h sleep, even after excluding those with baseline illness and adjusting for baseline health (HR=1·29 [1·08-1·53], P=0.004). This suggests the association is valid and does not simply reflect confounding or reverse causation. Meta-analysis of ten prospective studies including 447,124 participants also confirmed an association between short sleep and incident diabetes (1·33 [1·20-1·48]). Obtaining less than 6 hours of sleep each night (compared to 7 hours) may increase type 2 diabetes risk by approximately 30%.