Beta cell function declines with age in glucose tolerant Caucasians

Pathophysiology of Prediabetes, Diabetes, and Diabetic Remission in Cats

Diabetes mellitus (DM) has a heterogenous cause, and the exact pathogenesis differs between patients. Most diabetic cats have a cause similar to human type 2 DM but, in some, DM is associated with underlying conditions, such as hypersomatotropism, hyperadrenocorticism, or administration of diabetogenic drugs. Predisposing factors for feline DM include obesity, reduced physical activity, male sex, and increasing age. Gluco(lipo)toxicity and genetic predisposition also likely play roles in pathogenesis. Prediabetes cannot be accurately diagnosed in cats at the current time. Diabetic cats can enter remission, but relapses are common, as these cats might have ongoing, abnormal glucose homeostasis.

Age-Related Sex Differences in Glucose Tolerance by 75 g Oral Glucose Tolerance Test in Japanese

To elucidate the age-related sex difference in glucose tolerance, we conducted 75 g oral glucose tolerance tests in 1156 participants. Participants were divided into four groups, namely, young (22−29) males, young females, middle-aged (>50) males, and middle-aged females. According to the Japanese Clinical Practice Guideline for Diabetes 2019, the prevalence of normal glucose tolerance (NGT) was significantly lower in middle-aged than in young participants. The prevalence of high-normal fasting plasma glucose (FPG) was higher, and NGT was lower in young males (high-normal FPG 15.2%, NGT 82.0%) than young females (high-FPG 3.9%, NGT 94.3%). Combined glucose intolerance (CGI) was higher and NGT was lower in middle-aged males (CGI 10.2%, NGT 25.2%) than in middle-aged females (CGI 3.3%, NGT 39.8%). FPG and body mass index (BMI) were the lowest and Homeostatic model assessment beta cell function (HOMA-β) was the highest in young females, followed by young males, middle-aged females, and middle-aged males. Multiple linear regression analysis revealed that BMI weakly correlated with HOMA-β and Matsuda index in all subjects except young females. The superior glucose tolerance in females was apparent in young, but attenuated in middle-aged females. The differences are due to the higher insulin secretion potential and lower BMI in young females.

Remission of type 2 diabetes after gastrectomy for gastric cancer: diabetes prediction score

BACKGROUND

Although type 2 diabetes (T2D) remission after gastric cancer surgery has been reported, little is known about the predictors of postoperative T2D remission.

METHODS

This study used data from a nationwide cohort provided by the National Health Insurance Service in Korea. We developed a diabetes prediction (DP) score, which predicted postoperative T2D remissions using a logistic regression model based on preoperative variables. We applied machine-learning algorithms [random forest, XGboost, and least absolute shrinkage and selection operator (LASSO) regression] and compared their predictive performances with those of the DP score.

RESULTS

The DP score comprised five parameters: baseline body mass index (< 25 or ≥ 25 kg/m²), surgical procedures (subtotal or total gastrectomy), age (< 65 or ≥ 65 years), fasting plasma glucose levels (≤ 130 or > 130 mg/dL), and antidiabetic medications (combination therapy including sulfonylureas, combination therapy not including sulfonylureas, single sulfonylurea, or single non-sulfonylurea]). The DP score showed a clinically useful predictive performance for T2D remission at 3 years after surgery [training cohort: area under the receiver operating characteristics (AUROC) 0.73, 95% confidence interval (CI), 0.71-0.75; validation cohort: AUROC 0.72, 95% CI 0.69-0.75], which was comparable to that of the machine-learning models (random forest: AUROC 0.71, 95% CI 0.68-0.74; XGboost: AUROC 0.70, 95% CI 0.67-0.73; LASSO regression: AUROC 0.75, 95% CI 0.73-0.78 in the validation cohort). It also predicted the T2D remission at 6 and 9 years after surgery.

CONCLUSIONS

The DP score is a useful scoring system for predicting T2D remission after gastric cancer surgery.

Diabetes and Cardiovascular Risk in Renal Transplant Patients

End-stage kidney disease (ESKD) is a main public health problem, the prevalence of which is continuously increasing worldwide. Due to adverse effects of renal replacement therapies, kidney transplantation seems to be the optimal form of therapy with significantly improved survival, quality of life and diminished overall costs compared with dialysis. However, post-transplant patients frequently suffer from post-transplant diabetes mellitus (PTDM) which an important risk factor for cardiovascular and cardiovascular-related deaths after transplantation. The management of post-transplant diabetes resembles that of diabetes in the general population as it is based on strict glycemic control as well as screening and treatment of common complications. Lifestyle interventions accompanied by the tailoring of immunosuppressive regimen may be of key importance to mitigate PTDM-associated complications in kidney transplant patients. More transplant-specific approach can include the exchange of tacrolimus with an alternative immunosuppressant (cyclosporine or mammalian target of rapamycin (mTOR) inhibitor), the decrease or cessation of corticosteroid therapy and caution in the prescribing of diuretics since they are independently connected with post-transplant diabetes. Early identification of high-risk patients for cardiovascular diseases enables timely introduction of appropriate therapeutic strategy and results in higher survival rates for patients with a transplanted kidney.

Do East Asians With Normal Glucose Tolerance Have Worse β-Cell Function? A Meta-Analysis of Epidemiological Studies

BACKGROUND

The difference in the relationship between β-cell function and insulin resistance among Africans, Caucasians and East Asians with normal glucose tolerance (NGT) was not well investigated.

METHODS

We searched PubMed and Web of Science with keywords and identified studies that used the homeostasis model assessment (HOMA) model to evaluate β-cell function (HOMA-B) and insulin sensitivity/resistance (HOMA-S/HOMA-IR) in certain ethnic groups. We used random-effect model to pool data of HOMAs and compared the combined data among the three ethnic groups using subgroup analysis. Linear regression analysis was used to estimate the coefficient of HOMA-S on HOMA-B in these ethnic groups.

RESULTS

We evaluated pooled data of HOMAs in eight African, 26 Caucasian, and 84 East Asian cohorts with NGT, and also 2,392, 6,645 and 67,317 individuals, respectively. The three ethnic groups had distinct HOMA-B but similar HOMA-IR. The regression coefficient of lnHOMA-B on lnHOMA-S was different between Africans and Caucasians (-1.126 vs -0.401, P = 0.0006) or East Asian (-1.126 vs -0.586, P = 0.0087), but similar between Caucasians and East Asians (-0.401 vs -0.586, P = 0.1282). The coefficient in all ethnic groups was similar when age, BMI, and gender were adjusted (African vs Caucasian P = 0.0885, African vs East Asian P = 0.1092, and Caucasian vs East Asian P = 0.6298).

CONCLUSIONS

In subjects with NGT, East Asians had lower HOMA-B but similar β-cell response relative to insulin resistance with Caucasians and Africans when age, BMI, and gender were controlled. This result may challenge the allegation that there was an Asian-specific diabetes phenotype with worse β-cell function.

Clinical and genetic risk factors for new-onset diabetes mellitus after transplantation (NODAT) in major transplant centres in Malaysia

Background

New-onset diabetes after transplantation (NODAT) is associated with reduced patient and graft survival. This study examined the clinical and selected genetic factors associated with NODAT among renal-transplanted Malaysian patients.

Methods

This study included 168 non-diabetic patients (58% males, 69% of Chinese ethnicity) who received renal transplantation between 1st January 1994 to 31st December 2014, and were followed up in two major renal transplant centres in Malaysia. Fasting blood glucose levels were used to diagnose NODAT in patients who received renal transplantation within 1 year. Two single nucleotide polymorphisms (SNPs), namely; rs1494558 (interleukin-7 receptor, IL-7R) and rs2232365 (mannose-binding leptin-2, MBL2) were selected and genotyped using Sequenom MassArray platform. Cox proportional hazard regression analyses were used to examine the risk of developing NODAT according to the different demographics and clinical covariates, utilizing four time-points (one-month, three-months, six-months, one-year) post-transplant.

Results

Seventeen per cent of patients (n = 29, 55% males, 69% Chinese) were found to have developed NODAT within one-year of renal transplantation based on their fasting blood glucose levels. NODAT patients had renal transplantation at an older age compared to non-NODAT (39.3 ± 13.4 vs 33.9 ± 11.8 years, p = 0.03). In multivariate analysis, renal-transplanted patients who received a higher daily dose of cyclosporine (mg) were associated with increased risk of NODAT (Hazard ratio (HR) =1.01 per mg increase in dose, 95% confidence interval (CI) 1.00–1.01, p = 0.002). Other demographic (gender, ethnicities, age at transplant) and clinical factors (primary kidney disease, type of donor, place of transplant, type of calcineurin inhibitors, duration of dialysis pre-transplant, BMI, creatinine levels, and daily doses of tacrolimus and prednisolone) were not found to be significantly associated with risk of NODAT. GA genotype of rs1494558 (HR = 3.15 95% CI 1.26, 7.86) and AG genotype of rs2232365 (HR = 2.57 95% CI 1.07, 6.18) were associated with increased risk of NODAT as compared to AA genotypes.

Conclusion

The daily dose of cyclosporine and SNPs of IL-7R (rs1494558) and MBL2 (rs2232365) genes are significantly associated with the development of NODAT in the Malaysian renal transplant population.

Fasting and Postprandial Hyperglycemia: Their Predictors and Contributions to Overall Hyperglycemia in Korean Patients with Type 2 Diabetes

BACKGROUND

This study aimed to identify factors that affect fasting hyperglycemia (FHG) and postprandial hyperglycemia (PPG) and their contributions to overall hyperglycemia in Korean patients with type 2 diabetes mellitus (T2DM).

METHODS

This was a retrospective study conducted on 194 Korean T2DM patients with 7-point self-monitoring blood glucose (SMBG) profiles plotted in 4 days in 3 consecutive months. We calculated the areas corresponding to FHG and PPG (area under the curve [AUC]FHG and AUCPPG) and contributions (%) in the graph of the 7-point SMBG data. The levels of glycated hemoglobin (HbA1c) were categorized by tertiles, and the contributions of FHG and PPG were compared.

RESULTS

The relative contribution of FHG increased (44.7%±5.6%, 58.0%±4.4%, 66.5%±2.8%; PANOVA=0.002, PTREND &lt;0.001), while that of PPG decreased (55.3%±5.5%, 42.0%±4.4%, 33.5%±2.8%; PANOVA=0.002, PTREND &lt;0.001) with the elevated HbA1c. Multivariate analysis showed that HbA1c (β=0.615, P&lt;0.001), waist circumference (β=0.216, P=0.042), and triglyceride (β=0.121, P=0.048) had a significant association with AUCFHG. Only HbA1c (β=0.231, P=0.002) and age (β=0.196, P=0.009) was significantly associated with AUCPPG.

CONCLUSION

The data suggested that in Korean T2DM patients, FHG predominantly contributed to overall hyperglycemia at higher HbA1c levels, whereas it contributed to PPG at lower HbA1c levels. It is recommended that certain factors, namely age, degree of glycemic control, obesity, or triglyceride levels, should be considered when prescribing medications for T2DM patients.

Postprandial glucose response moderation by cardiorespiratory fitness following short exercise bouts

BACKGROUND

Previous reports indicate that postprandial glucose (PPG) responses to exercise may depend on cardiorespiratory fitness (CRF), such that less fit individuals have greater reductions in PPG with exercise. Our aim was to investigate moderating effects of CRF on PPG response following exercise of progressively shorter durations and sedentary rest.

METHODS

Thirty-four participants (14 female) completed a 75-g oral glucose tolerance test (OGTT) at seated rest. On three subsequent visits, participants completed additional OGTT with either 1, 3, or 10 minutes of stair-climbing. Fingerstick blood glucose measurements were taken every 15 minutes for 1 hour. CRF was determined using a treadmill ramp test.

RESULTS

There was a main effect of condition F(3, 93)=13.07, P<0.001, ηp2=0.30. Stair-climbing reduced PPG iAUC compared to control by -3±27% (P=0.546), -11±29% (P=0.091), and -28±22% (P<0.000) for the 1, 3 and 10 min bouts, respectively. There was no trial by CRF interaction for glucose iAUC F(2.4, 73.8)=0.69, P=0.532, ηp2=0.02. Linear mixed model regression analysis revealed that CRF was not significantly associated with glucose iAUC, b=-14 (-45, 16), P=0.339.

CONCLUSIONS

Contrary to previous reports CRF did not moderate PPG responses for either sedentary or exercise conditions in healthy men and women. Short, single-bout stair stepping exercise at a self-selected pace is equally efficient for all fitness levels.

Predictors of Long-Term Glycemic Remission After 2-Week Intensive Insulin Treatment in Newly Diagnosed Type 2 Diabetes

CONTEXT

Although several studies suggest that improved β-cell function is a key determinant of glycemic remission in type 2 diabetes, other predictors remain unclear.

OBJECTIVE

The aim of this clamp-based study was to identify predictors of 2-year glycemic remission after short-term intensive insulin treatment.

DESIGN

A 2-year follow-up was planned in 124 drug-naive patients with type 2 diabetes who received continuous subcutaneous insulin infusion (CSII) for 2 weeks. Euglycemic-hyperinsulinemic clamps and IV glucose tolerance tests were performed to assess the insulin sensitivity [glucose infusion rate (GIR)] and acute insulin response (AIR) before and after CSII.

RESULTS

First-phase insulin secretion was restored, and the GIR was significantly improved (P < 0.0001) after the 2-week CSII. Glycemic remission rates were 47.6% and 30.7% after 12 and 24 months of follow-up, respectively. Cox analysis revealed that a higher post-CSII glucose level [hazard ratio (HR), 1.38; 95% CI, 1.15 to 1.66; P = 0.0005] and older age at diabetes diagnosis (HR, 1.34; 95% CI, 1.05 to 1.72; P = 0.02) accounted for an increased risk of hyperglycemic relapse. A 1 SD increase in the AIR (HR, 0.75; 95% CI, 0.57 to 0.99; P = 0.04), GIR (HR, 0.67; 95% CI, 0.48 to 0.93; P = 0.016) after CSII, and baseline GIR (HR, 0.71; 95% CI, 0.51 to 0.99; P = 0.047) was inversely associated with this risk.

CONCLUSIONS

Younger age at diabetes diagnosis, higher baseline insulin sensitivity, and lower glucose levels after insulin treatment significantly favored a 2-year glycemic remission. This long-term remission was attributed to both improved insulin sensitivity and enhanced β-cell function after short-term intensive insulin treatment.

Sex and age discrepancy of HbA1c and fetal hemoglobin determined by HPLC in a large Chinese Han population

BACKGROUND

It is accepted that HbA1c is an effective indicator to evaluate glycemic control. Fetal hemoglobin (HbF) is seldom measured because traditional detection is inconvenient. In this regard, there may be an advantage in using HPLC autoanalysis of HbA1c as a surrogate method for HbF detection. The aim of the present study was to explore the distribution of HbA1c and HbF in a large Chinese Han population.

METHODS

In all, 70 553 blood samples were collected between January 2012 and June 2016. Study subjects were inpatients undergoing routine medical care and were divided into four groups based on age: Group A, 20-39 years; Group B, 40-59 years; Group C, 60-79 years; and Group D, ≥80 years. Blood HbA1c and HbF concentrations were measured by HPLC using a Tosho Bioscience (Tokyo, Japan) G8 analyzer.

RESULTS

There was a positive association between HbA1c and age, and a negative association between HbF and age. The concentration range of HbF was narrow and HbF concentrations were significantly higher in females than males, regardless of age (median 0.7% vs 0.6%, respectively; P < 0.0001). There was a low degree of correlation between HbF and HbA1c (r = 0.181, P < 0.0001). Although median HbA1c levels were higher in male than female subjects aged 20-59 years (5.5% vs 5.4%, respectively, in Group A; 5.9% vs 5.8%, respectively in Group B), in the 60-79 years group, HbA1c levels were lower in males than females (6.1% vs 6.2%, respectively; P < 0.0001).

CONCLUSIONS

The data suggest that sex and age should be considered in clinical interpretation of HbA1c.

Beta-cell Insufficiency

‘Beta-cell failure’ is a frequently used term to describe the structural and functional inability of the cells to fulfil their metabolic responsibility. This editorial reviews the anatomy and physiology of the beta cell, and describes factors which regulate this. The authors focus on semantics, comparing the phrases ‘beta-cell failure’, ‘functional mass’, and ‘beta-cell insufficiency’. They suggest the use of ‘beta-cell insufficiency’, with descriptors such as ‘partial’ and ‘complete’, or ‘reversible’ and ‘irreversible’, to convey betacell dysfunction in type 2 diabetes. A three-phase taxonomic structure: beta-cell sufficiency, partial/reversible beta-cell insufficiency and complete/irreversible beta-cell insufficiency, is proposed as a tool to understand pathophysiology and facilitate therapeutic decision-making.

Association of arsenobetaine with beta-cell function assessed by homeostasis model assessment (HOMA) in nondiabetic Koreans: data from the fourth Korea National Health and Nutrition Examination Survey (KNHANES) 2008-2009

Background

Arsenic is known as an endocrine disruptor that people are exposed to through various sources such as drinking water and indigestion of marine products. Although some epidemiological and animal studies have reported a correlation between arsenic exposure and diabetes development, there are limited studies regarding the toxic effects of organic arsenic including arsenobetaine on the human body. Here, we analyzed the association between urine arsenobetaine and the homeostasis model assessment of β-cell function (HOMA-β), which is an index for predicting diabetes development and reflecting the function of pancreatic β-cells.

Methods

In the fourth Korea National Health and Nutrition Examination Survey (KNHANES), health and nutrition surveys and screening tests were performed. Of the total survey population, people with confirmed values for urine total arsenic and arsenobetaine were included, and known diabetic patients were excluded. A total 369 participants were finally included in the study. We collected surveys on health, height, body weight, body mass index, blood mercury level, fasting glucose level, and serum insulin level and calculated HOMA index. Owing to sexual discrepancy, we performed sexually stratified analysis.

Results

Urine total arsenic and total arsenic minus arsenobetaine was not associated with HOMA-IR and HOMA-β in univariate analysis or in sexually stratified analysis. However, urine arsenobetaine showed a statistically significant relationship with HOMA-β in univariate analysis, and only male participants showed a significant correlation in sexually stratified analysis. In the analysis adjusted for age, BMI, smoking, alcohol drinking, physical activity and blood mercury, the HOMA-β value in the group below the 25th percentile of arsenobetaine was significantly higher than the group between 50 and 75th percentile, while no difference was shown for HOMA-IR. In sexually stratified analysis, The value of HOMA-β was significantly higher in male participants with below the 25th percentile urine arsenobetaine than the group between 25 and 50th and between 50 and 75th, while no difference was shown for HOMA-IR. However, female participants did not demonstrate a relationship between HOMA–IR, HOMA-β and urine arsenobetaine.

Conclusion

This study revealed the association between urine arsenobetaine and pancreatic β-cell function assessed by HOMA-β in the normal population (without diabetes), especially in males, despite adjusting for factors affecting pancreatic β-cell function and diabetes.

Electronic supplementary material

The online version of this article (doi:10.1186/s40557-017-0181-0) contains supplementary material, which is available to authorized users.

Efficacy and safety of thrice-weekly insulin degludec in elderly patients with type 2 diabetes assessed by continuous glucose monitoring

As life expectancy becomes longer in Japan, there has been an increase of elderly patients with type 2 diabetes who need insulin therapy but cannot perform self-injection due to dementia or other conditions. Therefore, the aim of this study was to investigate the efficacy and safety of thrice-weekly insulin degludec therapy in elderly patients with poorly controlled diabetes. The subjects were 22 hospitalized elderly Japanese patients with type 2 diabetes who had difficulty with self-injection. After becoming stable on once-daily insulin degludec treatment, they were assigned to continue once-daily injection (OD group) or were switched to thrice-weekly injection (TW group) for one week. In the TW group, insulin degludec (IDeg) was injected at twice the OD dose before lunch on Monday, Wednesday, and Friday. Glycemic control was assessed by continuous glucose monitoring (CGM) over 7 days. The mean 7-day glucose level (131±25 mg/dL with OD vs. 152±30 mg/dL with TW, p=0.11) and the mean 7-day standard deviation (32±10 mg/dL with OD vs. 36±14 mg/dL with TW, p=0.45) did not differ significantly between the two groups. The percent duration of glucose <70 mg/dL (2.4±3.1% with OD vs. 1.3±2.5% with TW, p=0.39) and glucose >200 mg/dL (7.2±12.1% with OD vs. 15.6±18.0% with TW, p=0.22) over 7 days also showed no significant differences between the two groups. In conclusion, thrice-weekly IDeg provided by a visiting nurse could be a practical option for elderly diabetic patients who have difficulty performing self-injection of insulin.

Decreased β-Cell Function Is Associated with Reduced Skeletal Muscle Mass in Japanese Subjects without Diabetes

BACKGROUND

Decreased insulin secretion has a great impact on the incidence of type 2 diabetes in Japanese subjects. It is not clear whether β-cell function is related to muscle mass in subjects without diabetes. We investigated the relationship between β-cell function and skeletal muscle mass in Japanese subjects without diabetes.

METHODS

The study included 1098 subjects (538 men and 560 women) aged 40 to 79 years, without diabetes (fasting glucose lower than 126 mg/dL and glycosylated hemoglobin lower than 6.5%), who consulted Osaka Medical College Health Science Clinic for a medical examination. Appendicular muscle mass was measured by bioelectrical impedance analysis. Appendicular muscle mass index was calculated as appendicular muscle mass divided by height squared (kg/m2). The homeostatic model assessment of β-cell function was used to assess β-cell function. The homeostatic model assessment of insulin resistance was used as a measure of insulin resistance. The association between appendicular muscle mass index and clinical parameters of β-cell function and insulin resistance was examined.

RESULTS

Log-transformed homeostatic model assessment of β-cell function and Log-transformed homeostatic model assessment of insulin resistance showed a normal distribution. In both men and women, there was a significant positive correlation between appendicular muscle mass index and clinical parameters of β-cell function and insulin resistance. Tertile analysis, following stratification according to appendicular muscle mass index, found that low appendicular muscle mass index was significantly associated with the Log homeostatic model assessment of β-cell function and Log-transformed homeostatic model assessment of insulin resistance.

CONCLUSION

This study shows that decreased β cell function is associated with reduced skeletal muscle mass in Japanese subjects without diabetes.

Efficacy and safety of lixisenatide in elderly (≥65 years old) and very elderly (≥75 years old) patients with type 2 diabetes: an analysis from the GetGoal phase III programme

BACKGROUND

The objective of this article is to evaluate the pharmacokinetics, efficacy and safety of lixisenatide (subcutaneous injection) in elderly (≥65 years old) and very elderly (≥75 years old) patients with type 2 diabetes mellitus.

METHODS

We conducted a phase I, single-centre, open-label study to evaluate the safety and pharmacokinetics of a single lixisenatide 20 µg dose and a pooled analysis of six randomized, placebo-controlled, phase III studies (12-month or 24-month duration) that evaluated glycaemic parameters and safety in patients receiving lixisenatide 20 µg once daily or placebo.

RESULTS

The pharmacokinetics study included 36 healthy subjects, including 18 elderly healthy subjects (≥65 years old) and 18 matched young healthy subjects (18-45 years old). The pooled analysis included 3188 patients, including 2565 patients <65 years old and 623 patients ≥65 years old (including 79 patients ≥75 years old). Mean exposure with lixisenatide 20 µg was ~30% higher in elderly than in young subjects, and the terminal half-life was prolonged by ~1.6 times. Maximum concentration (C(max)) and time to C(max) (t(max)) were comparable in both groups. Equal numbers of elderly and young subjects reported treatment-emergent adverse events, the majority of which were gastrointestinal disorders. In the pooled analysis, lixisenatide 20 µg once daily provided significant reductions in HbA1c versus placebo for all age groups. There was a similar incidence of treatment-emergent adverse events across all age groups (range: 69-73%). The incidence of symptomatic hypoglycaemia was generally comparable between lixisenatide-treated and placebo-treated patients.

CONCLUSION

These data suggest that lixisenatide is effective and well tolerated in elderly and very elderly patients with type 2 diabetes mellitus.

Associations of serum uric acid levels with cardiovascular health factors: differences by sex, age and body mass index in Chinese participants

BACKGROUND

Recently, the American Heart Association developed a set of 3 ideal cardiovascular (CV) health factors. However, information on whether associations of uric acid (UA) with the CV health factors is influenced by sex, age, and body mass index (BMI) is limited.

METHODS

We conducted a cross-sectional analysis using a cohort of 10,420 people aged 20-100 years, who underwent health checkups in 2009. CV health factors were defined as untreated total cholesterol (TC)<200mg/dl, untreated systolic/diastolic blood pressure (BP)<120/80 mm Hg, and untreated fasting plasma glucose (FPG)<100mg/dl.

RESULTS

The association of UA with each CV health factor was gender-specific. The interaction terms (gender × UA level) comparing change in prevalence of each CV health factor between the 1st and 4th UA quartiles showed a significantly greater reduction among women (all P<0.01). In addition, the interactions between UA levels and age on prevalence of each CV health factor were statistically significant (all P<0.01). Furthermore, absolute reductions in the prevalence of ideal levels of BP, and TC across ordinal UA quartiles were greater in obese individuals than in overweight and normal-weight individuals (all P<0.01). Finally, UA showed a bell-curved relation with the prevalence of ideal FPG among all BMI categories.

CONCLUSIONS

Elevated UA inversely associated with each CV health factor and these associations were influenced by gender, age and BMI. Elevated UA levels should alert clinical suspicion for a potential coexistence of low frequency of CV health factors.

Determinants of successful glycemic control among participants in the BARI 2D trial: a post-hoc analysis

OBJECTIVE

The BARI 2D trial compared insulin provision (IP) versus insulin sensitization (IS) for the primary outcome of total mortality in participants with T2DM and cardiovascular disease (CVD). In this analysis we examine baseline characteristics that are associated with successful long-term glycemic control.

RESEARCH DESIGN AND METHODS

In a 2×2 factorial design, 2368 participants were randomized to either IP or IS therapy, and to either prompt revascularization with medical therapy or medical therapy alone. Successful long-term glycemic control (success) was defined by simultaneously meeting 1) a mean HbA1c level of <7.0% after each participant's third year of follow-up period, and 2) adherence with medications only from the assigned glycemic treatment arm during >80% of the BARI 2D follow-up. The association between baseline variables and success was determined using unadjusted and adjusted logistic regression models.

RESULTS

1917 participants (962 IP and 955 IS participants) had sufficiently long follow-up and data for this analysis. Among these IP and IS participants, 235 and 335 participants met both criteria of success, respectively (p<0.001). Those not on insulin at entry had higher odds of success (OR 2.25; CI 1.79-2.82) when treated with IS versus IP medications, irrespective of baseline HbA1c levels. Younger age, shorter duration of T2DM, and lower HbA1c at baseline were also each independently associated with higher success when treated with IS versus IP medications.

CONCLUSION

Patients similar to those in the BARI 2D trial may have a higher chance of achieving success with IS versus IP medications if they are younger, have shorter duration of T2DM, have lower HbA1c levels, have moderate or strenuous physically activity, and are not on insulin. In contrast, increasing age, longer duration of T2DM, higher HbA1c, and insulin therapy are associated with increased chance of success if treated with IP medications.

The association of maximum body weight on the development of type 2 diabetes and microvascular complications: MAXWEL study

BACKGROUND

Obesity precedes the development of type 2 diabetes (T2D). However, the relationship between the magnitude and rate of weight gain to T2D development and complications, especially in non-White populations, has received less attention.

METHODS AND FINDINGS

We determined the association of rate and magnitude of weight gain to age at T2D diagnosis (Age(T2D)), HbA1c at T2D diagnosis (HbA1c(T2D)), microalbuminuria, and diabetic retinopathy after adjusting for sex, BMI at age 20 years, lifestyles, family history of T2D and/or blood pressure and lipids in 2164 Korean subjects aged ≥30 years and newly diagnosed with diabetes. Body weight at age 20 years (Wt(20y)) was obtained by recall or from participants' medical, school, or military records. Participants recalled their maximum weight (Wt(max)) prior to T2D diagnosis and age at maximum weight (Age(max_wt)). The rate of weight gain (Rate(max_wt)) was calculated from magnitude of weight gain (ΔWt = Wt(max)-Wt(20y)) divided by ΔTime (Age(max_wt) -20 years). The mean Age(max_wt) and Age(T2D) were 41.5±10.9 years and 50.1±10.5 years, respectively. The Wt(20y) and Wt(max) were 59.9±10.5 kg and 72.9±11.4 kg, respectively. The Rate(max_wt) was 0.56±0.50 kg/year. After adjusting for risk factors, greater ΔWt and higher Rate(max_wt) were significantly associated with earlier Age(T2D), higher HbA1c(T2D) after additional adjusting for Age(T2D), and microalbuminuria after further adjusting for HbA1c(T2D) and lipid profiles. Greater ΔWt and higher Rate(max_wt) were also significantly associated with diabetic retinopathy.

CONCLUSIONS

This finding supports public health recommendations to reduce the risk of T2D and its complications by preventing weight gain from early adulthood.

Alcohol use behaviors, fat intake and the function of pancreatic β-cells in non-obese, healthy Korean males: findings from 2010 Korea National Health and Nutrition Examination Survey

AIMS

In the present study, we aimed to identify dietary factors related to insulin secretion function especially in healthy, non-obese Korean males.

METHODS

Data were obtained from the Korea National Health and Nutrition Examination Survey V-1 (KNHANES V-1). Nine hundred and twenty male adults aged >30 years of normal weight were included, excluding those with type 2 diabetes mellitus and liver disease. Alcohol use disorders identification test (AUDIT) score which represents alcohol use behaviors and nutrient intakes was used, and homeostasis model assessment of β-cell function (HOMA-B score) was calculated.

RESULTS

HOMA-B score was associated with age (p < 0.001), AUDIT score (p = 0.030), and percentage of fat from total energy intake (p = 0.002). HOMA-B scores in the problematic AUDIT group were significantly lower than those in the normal AUDIT group. In addition, HOMA-B scores in the lowest fat intake group were significantly lower than those in the medium fat intake group, but similar to those in the highest fat intake group. There was an interaction between alcohol use behaviors and percentage of fat from energy intake in determining HOMA-B score (p for interaction = 0.034).

CONCLUSIONS

Alcohol use behaviors and percentage of fat from energy intake were found to be associated with HOMA-B score in healthy, non-obese Korean males.

The ageing pancreas

Type 2 diabetes is historically associated with older adults, and glucose tolerance is known to decline with advancing age. During the course of natural ageing, changes in many peripheral tissues contribute to this deterioration of glucose homeostasis. Included in this process are changes to the structure and function of the pancreatic islets, which undergo deviation in endocrine responses to glycaemic challenge. Current knowledge about the changes seen in the ageing pancreas is reviewed here.

New approach to beta cell function screening by nitric oxide assessment of obese individuals at the population level

Background

Approximately 27% of Americans today are obese, and this condition increases the prevalence of metabolic syndrome and diabetes. The UK Prospective Diabetes Study suggests that loss of beta cell function can begin at least 10 years before diagnosis, and mean beta cell function is already less than 50% at diagnosis. The aim of this research was to assess the possibility of detecting loss of beta cell function in obese patients by a novel approach involving nitric oxide assessment using a combination of technologies.

Materials and methods

One hundred and fifteen obese patients (93 women, 22 men) of mean age 39 (range 17–62) years, who were candidates for bariatric surgery were included in the study, and underwent laboratory tests, including fasting blood glucose, fasting insulin plasma, and examination with the Electro Sensor complex. The Electro Sensor complex offers a new way to assess nitric oxide production using five technologies managed by software, ie, the galvanic skin response, photoelectrical plethysmography, heart rate variability analysis, bioimpedance analysis, and blood pressure oscillometric measurements. The homeostasis model assessment 2% beta cell function (HOMA2% β) algorithm was calculated from fasting blood glucose and fasting insulin plasma using free software provided by The University of Oxford Diabetes Trial Unit. The Electro Sensor complex percent beta (ESC% β) algorithm was calculated from the Electro Sensor complex data and statistical neural network. Statistical analysis was performed to correlate ESC% β and HOMA2% β using the coefficient of correlation and Spearman’s coefficient of rank correlation. Receiver-operating characteristic curves were also constructed to determine the specificity and sensitivity of ESC% β in detecting a HOMA2% β value < 100.

Results

The coefficient of correlation between ESC% β and HOMA2% β was 0.72 (using log values) and the Spearman’s coefficient of rank correlation (rho) was 0.799 (P < 0.0001). ESC% β had a sensitivity of 77.14% and specificity of 78.21% (cutoff ≤ 157, corresponding to 40% after conversion into a 0%–100% scale) to detect a HOMA2% β value < 100 (P < 0.0001).

Conclusion

The ESC% β algorithm has a high predictive correlation with HOMA2% β, and good specificity and sensitivity to detect a HOMA2% β value < 100. Therefore, the Electro Sensor complex enabling nitric oxide assessment represents a novel method of screening for beta cell function in the obese population on a large scale. Such a tool, which is easy to administer, noninvasive, and cost-effective, would be of great benefit for widespread screening of beta cell function in obese patients.

Excess body mass index-years, a measure of degree and duration of excess weight, and risk for incident diabetes

OBJECTIVE

To evaluate the relation between excess body mass index (BMI)-years, a measure of the degree to which an individual's BMI (calculated as weight in kilograms divided by height in meters squared) exceeds the reference BMI and the duration for which he or she carries excess BMI, and incident diabetes.

DESIGN

Longitudinal analysis.

SETTING

United States of America.

PARTICIPANTS

A total of 8157 adolescents and young adults aged 14 to 21 years at the start of the National Longitudinal Survey of Youth 1979 with self-reported measures of height, weight, and diabetes status (type unspecified) from 1981 through 2006.

MAIN EXPOSURE

Excess BMI-years, which were calculated by subtracting the [corrected] reference BMI (25.0 for adults or 85th percentile for adolescents) from the actual BMI [corrected] for each study year and cumulating excess BMI for the study duration.

MAIN OUTCOME MEASURE

We conducted logistic regression models to predict presumed type 2 diabetes (after excluding presumed type 1 diabetes) as a function of age, sex, race, excess BMI-years, and specific interactions.

RESULTS

A higher level of excess BMI-years was associated with an increased risk of diabetes. For example, on average, white men aged 40 years with 200 excess BMI-years had 2.94 times (95% confidence interval, 2.36-3.67) higher odds of developing diabetes compared with men of the same age and race with 100 excess BMI-years. For a given level of excess BMI-years, younger compared with older and Hispanic and black compared with white individuals had higher risk of developing diabetes. Our study is limited by use of self-reported data without specification of diabetes type.

CONCLUSIONS

Because younger compared with older individuals have a higher risk of self-reported diabetes for a given level of excess BMI-years and cumulative exposure to excess BMI is increasing among younger US birth cohorts, public health interventions should target younger adults.

Type 2 diabetes and the aging pancreatic beta cell

The incidence of and susceptibility to Type 2 diabetes increases with age, but the underlying mechanism(s) within beta cells that contribute to this increased susceptibility have not been fully elucidated. Here we review how aging affects the proliferative and regenerative capacity of beta cells and how this impacts beta cell mass. In addition we review changes that occur in beta cell function with age. Although we focus on the different rodent models that have provided insight into the characteristics of the aging beta cell, the limited knowledge from non-rodent models is also reviewed. Further studies are needed in order to identify potential beta cell targets for preventing or slowing the progression of diabetes that occurs with age.

Glucocorticoid-induced diabetes mellitus in patients with systemic lupus erythematosus treated with high-dose glucocorticoid therapy

The aim of this study was to investigate the prevalence and associated factors of glucocorticoid-induced diabetes mellitus (GDM) in patients with systemic lupus erythematosus (SLE) receiving high-dose glucocorticoid therapy. Patients with SLE who had received high-dose glucocorticoid therapy (prednisolone ≥1 mg/kg/day) at Yonsei University Medical Center, Seoul, Korea, were recruited between January 1999 and June 2009. In total 127 patients with SLE were evaluated. Sixteen (12.6%) of them developed GDM after high-dose glucocorticoid therapy (95% confidence interval, 6.8-18.4%). Univariate analysis showed that old age, family history of diabetes mellitus (DM), hypertension, higher body mass index, higher mean dose of prednisolone before high-dose glucocorticoid therapy, and concurrent use of mycophenolate mofetil (MMF) were factors that would increase the likelihood of GDM. Multivariate analysis determined that age, family history of DM, mean dose of prednisolone before high-dose glucocorticoid therapy and concurrent use of MMF were independent associated factors for GDM. In summary, GDM was developed among 12.6% of patients with SLE after high-dose glucocorticoid therapy. Old age, family history of DM, higher mean dose of prednisolone before high-dose glucocorticoid therapy and concurrent use of MMF were determined to be factors responsible for increasing the risk of developing GDM.

Exacerbated postprandial oxidative stress induced by the acute intake of a lipid meal compared to isoenergetically administered carbohydrate, protein, and mixed meals in young, healthy men

OBJECTIVE

To compare the oxidative stress response following isocaloric consumption of a lipid, carbohydrate, protein, and mixed meal.

DESIGN

Ten young (27.3 ± 7.0 years), healthy (body mass index = 24.9 ± 4.0 kg·m(-2)) men consumed isocaloric test meals on 4 separate days, separated by 1 week, in a random-order crossover design. Blood samples were collected premeal and at 1, 2, 4, and 6 hours postmeal and assayed for various markers of oxidative stress, as well as triglycerides (TAG) and glucose. Total area under the curve (AUC) was calculated for each variable, and a 4 × 5 analysis of variance (ANOVA) was used to further analyze data.

RESULTS

Significant meal effects were noted for hydrogen peroxide AUC (p = 0.004), with values higher for the lipid meal compared with all other meals (p < 0.05). Contrasts revealed greater AUC for TAG (p = 0.05), malondialdehyde (p = 0.002), and nitrate/nitrite (p = 0.02) for the lipid meal compared with the protein meal. With regard to the ANOVA, oxidative stress values were highest for the lipid meal and increased from 2-6 hours postmeal following lipid ingestion (p < 0.05). No other meals resulted in a significant increase in oxidative stress (p > 0.05).

CONCLUSIONS

These data indicate that when controlling for total dietary energy, a lipid meal results in the greatest increase in postprandial oxidative stress in a sample of young, healthy men.

Age-related changes in insulin sensitivity and β-cell function among European-American and African-American women

Type 2 diabetes (T2D) is more prevalent among African-American (AA) than European-American (EA) women for reasons that are unknown. Ethnic differences in physiological processes related to insulin sensitivity (S(I)) and secretion, and age-related changes in these processes, may play a role. The purpose of this study was to identify ethnicity- and age-related differences in S(I) and β-cell responsivity among AA and EA females, and to determine whether these differences are independent of body composition and fat distribution. Healthy, normoglycemic females aged 7-12 years (n = 62), 18-32 years (n = 57), and 40-70 years (n = 49) were recruited for entry into this study. Following an overnight fast, S(I), intravenous glucose tolerance (Kg), acute C-peptide secretion (X0), and basal, first-phase, second-phase, and total β-cell responsivity to glucose (PhiB, Phi1, Phi2, and Phi(TOT), respectively) were measured by an intravenous glucose tolerance test. Total % body fat was assessed by dual-energy X-ray absorptiometry, and intra-abdominal adiposity (IAAT) by computed tomography. Main effects of age group and ethnicity were measured with analysis of covariance, adjusting for % fat, IAAT, and S(I) as indicated. AA had lower S(I), and higher Kg, X0, Phi1, and Phi(TOT) (P < 0.05), which remained after adjustment for % fat and IAAT. Greater X0, Phi1, and Phi(TOT) among AA were independent of S(I). Advancing age was associated with greater Phi2 among both EA and AA. To conclude, inherent ethnic differences in β-cell function exist independently of adiposity and S(I). Future research should examine whether ethnic differences in β-cell physiology contribute to disparities in T2D risk.

Effect of Metformin on Hormonal and Biochemical Profile in PCOS Before and After Therapy

Insulin resistance and the resultant hyperinsulinemia exacerbate the reproductive abnormalities of Polycystic Ovarian Syndrome by increasing ovarian androgen productions and decreasing serum sex hormone binding globulin. The present study was conducted to estimate serum insulin and testosterone level in 44 PCOS cases and 32 control patients. Simultaneously the role of metformin (an insulin sensitizing agent) in modulating insulin resistance and serum androgen level was also analyzed. A significant rise in serum insulin and testosterone (P < 0.001) was observed in cases in comparison to control. Fasting Plasma Glucose to insulin ratio, a marker of insulin resistance revealed a significant fall in PCOS group. Follow up of cases with metformin for 3 months revealed a significant fall in serum insulin (P < 0.05) with improvement in insulin resistance along with a nonsignificant fall in testosterone level. Serum insulin registered a significant positive correlation (P < 0.05) with serum testosterone revealing its etiological association. Thus administration of drugs ameliorating insulin levels is expected to provide new therapeutic modality for PCOS.

β-cell function is associated with metabolic syndrome in Mexican subjects

AIMS

The clinical diagnosis of metabolic syndrome does not find any parameters to evaluate the insulin sensitivity (IS) or β-cell function. The evaluation of these parameters would detect early risk of developing metabolic syndrome. The aim of this study is to determine the relationship between β-cell function and presence of metabolic syndrome in Mexican subjects.

MATERIAL AND METHODS

This study is part of the Mexican Survey on the Prevention of Diabetes (MexDiab Study) with headquarters in the city of Puebla, Mexico. The study comprised of 444 subjects of both genders, aged between 18 and 60 years and allocated into two study groups: (1) control group of individuals at metabolic balance without metabolic syndrome and (2) group composed of subjects with metabolic syndrome and diagnosed according to the criteria of the Third Report of the National Cholesterol Education Program Expert Panel on Defection, Evaluation, and Treatment of High Blood Cholesterol in Adults. Anthropometric, biochemical, and clinical assessments were carried out.

RESULTS

Average age of the subjects in the control group (n = 254) was 35.7 ± 11.5 years and 42.0 ± 10.7 years for subjects in the metabolic syndrome group (n = 190). Subjects at metabolic balance without metabolic syndrome showed decreased IS, increased insulin resistance (IR), and altered β-cell function. Individuals with metabolic syndrome showed a high prevalence (P ≤ 0.05) of family history of type 2 diabetes (T2D). This group also showed a significant metabolic imbalance with glucose and insulin levels and lipid profile outside the ranges considered safe to prevent the development of cardiovascular disease and T2D.

CONCLUSION

The main finding in this study was the detection of altered β-cell function, decreased IS, an increased IR in subjects at metabolic balance, and the progressive deterioration of β-cell function and IS in subjects with metabolic syndrome as the number of features of metabolic syndrome increases.

Does abnormal insulin action or insulin secretion explain the increase in prevalence of impaired glucose metabolism with age in populations of different ethnicities?

BACKGROUND

Age is associated with both impaired glucose and insulin metabolism. To what extent the age-related changes in insulin resistance (IR) and beta-cell function contribute to the increase in prevalence of impaired fasting glucose (IFG) and impaired glucose tolerance (IGT) is less known, and this is investigated in this study.

METHODS

This study included 6610 men and 7664 women of different ethnic groups aged 30-69 years. IR and beta-cell function were examined by the homeostasis model assessment of insulin resistance (HOMA-IR) and homeostasis model assessment of beta-cell function (HOMA-B). Odds ratios (ORs) and 95% confidence intervals (95% CIs) were estimated using logistic regression analysis adjusting for body mass index and study.

RESULTS

In Chinese men, the ORs (95% CIs) for IFG were 2.69 (1.70, 4.26), 2.51 (1.49, 4.21) and 2.89 (1.68, 4.97), respectively, in age groups of 40-49, 50-59 and 60-69 years compared with 30-39 years (p < 0.001 for trend); the corresponding figures for IGT were 1.73 (1.25, 2.38), 2.54 (1.78, 3.63) and 3.57 (2.46, 5.19) (p < 0.001 for trend). Similar trends for IGT were observed also in Chinese women and other ethnic groups, but not for IFG in Mauritius Indian and Creole men. Adjustment for HOMA-IR and HOMA-B reduced the ORs in all age groups of all ethnicities for both IFG and IGT, but the risk gradient between age groups remained particularly for the IGT.

CONCLUSIONS

The age-related increase in glucose intolerance may not be fully explained by the defect in HOMA-IR and HOMA-B. As HOMA-IR and HOMA-B are only surrogate measures of insulin sensitivity and insulin secretion, the results need to be further investigated.

Treatment Considerations for Diabetes: A Pharmacist’s Guide to Improving Care in the Elderly

The management of diabetes in elderly patients has many nuances that are important to the pharmacist, regardless of his or her practice setting. General guidelines and treatment modalities applied to the younger population cannot necessarily be applied to the elderly population and in most cases, should be tailored to meet their needs. The purpose of this article is to gain a better understanding of the complex nature of diabetes and management in the elderly by (1) reviewing the pathogenesis and pathophysiology of diabetes in the patients, (2) understanding complications and geriatric syndromes that may affect management of diabetes, (3) becoming familiar with nationally accepted diabetes care guidelines in the elderly, (4) reviewing recent literature pertaining to management of diabetes, and (5) reviewing medications (including newer agents) to treat diabetes in the elderly.

The effect of age on insulin sensitivity and insulin secretion in first-degree relatives of type 1 diabetic patients: a population analysis

CONTEXT

Understanding the role of insulin resistance in type 1 diabetes may lead to new prevention strategies. Estimates of insulin resistance in first-degree relatives of those with type 1 diabetes may be obtained using the minimal model of glucose kinetics incorporating a population approach.

OBJECTIVE

The objective of the study was to explore parameters contributing to glucose homeostasis in a cross-sectional study of first-degree relatives across a wide age range.

DESIGN

Insulin sensitivity (SI) was assessed using the minimal model of glucose kinetics after an oral glucose tolerance test combined with nonlinear mixed-effects modeling. Beta-cell function was measured from the insulinogenic index at 30 min (IGI(30)). Disposition index (DI) was estimated as the product of SI and IGI(30).

SETTING

The study was conducted at an academic center.

SUBJECTS

Subjects included 1241 first-degree relatives (aged 2-75 yr).

RESULTS

SI was found to be negatively correlated with age, whereas IGI(30) increased until young adulthood. The increase IGI(30) was apparently insufficient to compensate for the insulin resistance because DI decreased linearly at the rate of 0.035 (10(-2) min(-1) mmol(-1) liter per year) after young adulthood. Both IGI(30) and DI were significantly lower in those with vs. without autoantibodies, whereas there was no difference between these groups with respect to SI.

CONCLUSIONS

Beta-cell function, adjusted for age-related insulin resistance, decreases throughout life in first-degree relatives. This deterioration may be exacerbated in the presence of autoantibodies. Oral glucose tolerance test data combined with a nonlinear mixed-effect modeling population approach may be a useful technique to evaluate SI and secretion in a population.

Ethnic, gender, and age-related differences in patients with the metabolic syndrome

The metabolic syndrome is a clustering of cardiovascular risk factors and is associated with an increased risk of developing diabetes, cardiovascular disease, and kidney disease. Epidemiologic studies have demonstrated differences in prevalence by age, gender, and ethnicity. The prevalence of the metabolic syndrome increases with age through the sixth decade of life among men and seventh decade among women. Most, but not all, studies reported a higher prevalence of the metabolic syndrome among women compared with men. Although the metabolic syndrome is more common among Mexican Americans compared with non-Hispanic whites and blacks, among men the metabolic syndrome is more common among non-Hispanic whites than non-Hispanic blacks; the reverse is true among women. Understanding the basic pathophysiology underlying the metabolic syndrome may help explain the age, gender, and ethnic differences in its prevalence and guide preventive and therapeutic efforts.

Effect of obesity on incidence of type 2 diabetes declines with age among Japanese women

AIMS

The present study sought to investigate whether the effect of obesity on the incidence of type 2 diabetes varies with age among Japanese.

METHODS

Employing two independent cohorts, one in Chiba City from 1994 to 2005 and the other in Kashiwa City from 2002 to 2006, the combined effect of body mass index (BMI) and age on the incidence of type 2 diabetes was evaluated by Cox regression analysis. A total of 37,564 and 26,959 subjects were enrolled in the cohorts and the follow-up rate was 94.7% and 93.3%, respectively.

RESULTS

In the Chiba cohort, the hazard ratio for incidence of type 2 diabetes was significantly higher in obese subjects (25.0 kg/m(2) < or = BMI) than in normal weight subjects (18.5 kg/m(2) < or = BMI < 25.0 kg/m(2)) across all age groups, with the highest hazard ratio observed in the youngest group aged 40-59 years. In the Kashiwa cohort, the hazard ratio was also significantly higher in obese subjects than in normal weight subjects in men aged 40-59 and 70-79 years and in women aged 40-59 years. Analysis for the interaction between age groups and obese subjects versus normal weight subjects revealed significant weakening of the effect of obesity in women in both cohorts in subjects aged 60-69 and 70-79 years compared to younger subjects aged 40-59 years. In men, however, a significant weakening of the effect was observed only in subjects aged 60-69 years in the Chiba cohort. The interaction between four BMI categories including an extremely obese group (30.0 kg/m(2) < or = BMI) and age category was significant in women (P < 0.001) but not in men (P = 0.113) in the Chiba cohort.

CONCLUSION

Based on data from the two independent cohorts, the effect of obesity on the incidence of type 2 diabetes was found to decline with age in Japanese women but not in men.

Reversal of type 2 diabetes mellitus and improvements in cardiovascular risk factors after surgical weight loss in adolescents

OBJECTIVES

Type 2 diabetes mellitus is associated with obesity, dyslipidemia, and hypertension, all well-known risk factors for cardiovascular disease. Surgical weight loss has resulted in a marked reduction of these risk factors in adults. We hypothesized that gastric bypass would improve parameters of metabolic dysfunction and cardiovascular risk in adolescents with type 2 diabetes mellitus.

PATIENTS AND METHODS

Eleven adolescents who underwent Roux-en-Y gastric bypass at 5 centers were included. Anthropometric, hemodynamic, and biochemical measures and surgical complications were analyzed. Similar measures from 67 adolescents with type 2 diabetes mellitus who were treated medically for 1 year were also analyzed.

RESULTS

Adolescents who underwent Roux-en-Y gastric bypass were extremely obese (mean BMI of 50 +/- 5.9 kg/m(2)) with numerous cardiovascular risk factors. After surgery there was evidence of remission of type 2 diabetes mellitus in all but 1 patient. Significant improvements in BMI (-34%), fasting blood glucose (-41%), fasting insulin concentrations (-81%), hemoglobin A1c levels (7.3%-5.6%), and insulin sensitivity were also seen. There were significant improvements in serum lipid levels and blood pressure. In comparison, adolescents with type 2 diabetes mellitus who were followed during 1 year of medical treatment demonstrated stable body weight (baseline BMI: 35 +/- 7.3 kg/m(2); 1-year BMI: 34.9 +/- 7.2 kg/m(2)) and no significant change in blood pressure or in diabetic medication use. Medically managed patients had significantly improved hemoglobin A1c levels over 1 year (baseline: 7.85% +/- 2.3%; 1 year: 7.1% +/- 2%).

CONCLUSIONS

Extremely obese diabetic adolescents experience significant weight loss and remission of type 2 diabetes mellitus after Roux-en-Y gastric bypass. Improvements in insulin resistance, beta-cell function, and cardiovascular risk factors support Roux-en-Y gastric bypass as an intervention that improves the health of these adolescents. Although the long-term efficacy of Roux-en-Y gastric bypass is not known, these findings suggest that Roux-en-Y gastric bypass is an effective option for the treatment of extremely obese adolescents with type 2 diabetes mellitus.

Effect of aging on glucose homeostasis: accelerated deterioration of beta-cell function in individuals with impaired glucose tolerance

OBJECTIVE

To examine the effect of aging on insulin secretion (first- and second-phase insulin release) and insulin sensitivity in people with normal glucose tolerance (NGT) or impaired glucose tolerance (IGT).

RESEARCH DESIGN AND METHODS

First- and second-phase insulin secretion and insulin sensitivity were assessed in hyperglycemic clamp experiments in 266 individuals with NGT and 130 individuals with IGT, ranging in age from approximately 20 to approximately 70 years. Changes in beta-cell function were compared using the disposition index to adjust for differences in insulin sensitivity.

RESULTS

As expected, both phases of insulin release and insulin sensitivity were reduced in individuals with IGT (all P < 0.01). Insulin sensitivity was not independently correlated with age in either group. In people with NGT, the disposition index for first- and second-phase insulin release decreased similarly at a rate of approximately 0.7% per year. In people with IGT, the disposition indexes for first- and second-phase insulin release decreased at greater rates ( approximately 2.2 and 1.4% per year, P = 0.002 and 0.009, respectively, vs. NGT), with the decrease in first phase being greater than that of second phase (P = 0.025).

CONCLUSIONS

Insulin secretion (both first and second phase) normally decreases at a rate of approximately 0.7% per year with aging; this decrease in beta-cell function is accelerated about two-fold in people with impaired glucose tolerance-first phase to a greater extent than second phase. Finally, aging per se has no effect on insulin sensitivity independent of changes in body composition.

Whole blood assays to identify Th1 cell antigens and peptides encoded by Mycobacterium tuberculosis-specific RD1 genes

OBJECTIVE

To identify Th1 cell-stimulating antigens/peptides encoded by the genes predicted in the Mycobacterium tuberculosis-specific genomic region of difference (RD)1, deleted in Mycobacterium bovis Bacille Calmette-Guérin(BCG), by using synthetic peptides and whole blood from tuberculosis (TB) patients.

MATERIALS AND METHODS

Heparinized peripheral blood was obtained from culture-proven pulmonary TB patients (n = 16) attending the Chest Disease Hospital, Kuwait. Whole blood was diluted with tissue culture medium RPMI-1640 and tested for Th1 cell stimulation using antigen-induced proliferation and interferon-gamma (IFN-gamma) secretion assays. The antigens included a peptide pool of 220 peptides covering the sequence of 12 open reading frames (ORFs) of RD1 (RD1(mix)), peptide pools of RD1 ORF5 (ORF5(mix)), ORF6 (ORF6(mix)) and ORF7 (ORF7(mix)), and individual peptides of ORF6 (P6.1-P6.6) and ORF7 (P7.1-P7.6). M. tuberculosis culture filtrate, cell walls and whole-cell M. bovis BCG were used as complex mycobacterial antigens. The results obtained with different antigens and peptides were statistically analyzed for significant differences using Z test.

RESULTS

The complex mycobacterial antigens (culture filtrate, cell walls and M.bovis BCG) and RD1(mix) induced comparable (p > 0.05) positive antigen-induced proliferation and IFN-gamma responses with whole blood from TB patients. However, the positive IFN-gamma responses induced by ORF6(mix) and ORF7(mix) were higher than ORF5(mix). Among the individual peptides, P6.4 and P7.1 of ORF6 and ORF7, respectively, induced the highest IFN-gamma responses, suggesting that these peptides represented the immunodominant Th1 cell epitopes of RD1 ORF6 and ORF7 in the patients tested.

CONCLUSION

The whole blood assays with synthetic peptides are useful to identify Th1 cell antigens/peptides encoded by genes located in M. tuberculosis-specific genomic regions.

Toward a control theory analysis of aging

Aging is due to the accumulation of damage over time that affects the function and survival of the organism; however, it has proven difficult to infer the relative importance of the many processes that contribute to aging. To address this, here we outline an approach that may prove useful in analyzing aging. In this approach, the function of the organism is described as a set of interacting physiological systems. Degradation of their outputs leads to functional decline and death as a result of aging. In turn, degradation of the system outputs is attributable to changes at the next hierarchical level down, the cell, through changes in cell number or function, which are in turn a consequence of the metabolic history of the cell. Within this framework, we then adapt the methods of metabolic control analysis (MCA) to determine which modifications are important for aging. This combination of a hierarchical framework and the methodologies of MCA may prove useful both for thinking about aging and for analyzing it experimentally.

Pancreatic beta-cell function as a predictor of cardiovascular outcomes and costs: findings from the Cardiovascular Health Study

OBJECTIVE

To explore relationships between beta-cell function and incident cardiovascular events, death, and medical costs among elderly individuals.

RESEARCH DESIGN AND METHODS

In a prospective, population-based cohort of 4555 elderly individuals, we examined the effect of beta-cell function on incident cardiovascular events and mortality. We also examined costs for 3715 of these individuals. We used the computer-based homeostasis model assessment (HOMA) to calculate indices of beta-cell function (HOMA-%B) and insulin sensitivity (HOMA-%S) using baseline fasting glucose and insulin levels. All subjects were followed from 1992/1993 for 6 years or until death.

MAIN OUTCOME MEASURES

Discrete-time survival model of the effects of beta-cell function on incident cardiovascular events and all-cause mortality; and semiparametric estimators for calculations of mean 6-year costs.

RESULTS

Controlling for HOMA-%S, a 20% decrease in HOMA-%B was associated with increased odds of incident cardiovascular events (odds ratio [OR], 1.09; 95% confidence interval [CI], 1.05-1.14) and death (OR, 1.10; 95% CI, 1.07-1.14). The relationships persisted after controlling for clinical and sociodemographic confounders. A 20% decrease in HOMA-%B was also associated with increased costs (cost ratio, 1.03; 95% CI, 1.01-1.05). The significant association did not persist after controlling for confounders.

LIMITATIONS

The sample comprises relatively healthy elderly individuals and is based on data from 1992 through 1999, which may not reflect current experience. The measure of beta-cell function is an estimate generated from single measures of glucose and insulin.

CONCLUSIONS

Beta-cell function as measured by HOMA-%B is a significant predictor of incident cardiovascular events and mortality but not of costs, controlling for HOMA-%S and sociodemographic and clinical confounders.

Gastric emptying, diabetes, and aging

Gastric emptying is mildly slowed in healthy aging, although generally remains within the normal range for young people. The significance of this is unclear, but may potentially influence the absorption of certain drugs, especially when a rapid effect is desired. Type 2 diabetes is common in the elderly, but there is little data regarding its natural history, prognosis, and management. This article focuses on the interactions between gastric emptying and diabetes, how each is influenced by the process of aging, and the implications for patient management.

Antihyperglycaemic therapy in elderly patients with type 2 diabetes: potential role of incretin mimetics and DPP-4 inhibitors

Management of elderly patients with type II diabetes is complicated by age-related changes in physiology, comorbidities, polypharmacy and heterogeneity of functional status. A minimum goal in antidiabetic treatment in this population is to achieve a level of glycaemic control that avoids acute complications of diabetes, adverse effects and reduction in quality of life. Hypoglycaemia is a particular problem in elderly patients, and many antidiabetic agents pose increased risk for hypoglycaemia. In addition, many standard agents pose risks for older patients because of reduced renal function and common comorbidities. Newer agents based on enhancing incretin activity, including the glucagon-like peptide-1 mimetics exenatide and liraglutide and the oral dipeptidyl peptidase-4 inhibitors sitagliptin and vildagliptin, may offer particular advantages in elderly patients with diabetes.

Risk factors associated with the onset and progression of posttransplantation diabetes in renal allograft recipients

OBJECTIVE

The aim of this study was to assess the incidence of posttransplantation diabetes mellitus (PTDM) in renal allograft recipients and to investigate factors contributing to the onset and progression of PTDM and its underlying pathogenic mechanism(s).

RESEARCH DESIGN AND METHODS

A total of 77 patients with normal glucose tolerance (NGT) were enrolled in this study. An oral glucose tolerance test was performed 1 week before transplantation and repeated at 1 and 7 years after transplantation.

RESULTS

The overall incidence of PTDM was 39% at 1 year and 35.1% at 7 years posttransplantation. The incidence for each category of PTDM was as follows: persistent PTDM (P-PTDM) (patients who developed diabetes mellitus within 1 year of transplantation and remained diabetic during 7 years), 23.4%; transient PTDM (T-PTDM) (patients who developed diabetes mellitus during the 1st year after transplantation but eventually recovered to have NGT), 15.6%; late PTDM (L-PTDM) (patients who developed diabetes mellitus later than 1 year after transplantation), 11.7%; and non-PTDM during 7 years (N-PTDM7) (patients who did not develop diabetes mellitus during 7 years), 49.3%. Older age (> or = 40 years) at transplantation was a higher risk factor for P-PTDM, whereas a high BMI (> or = 25 kg/m2) and impaired fasting glucose (IFG) at 1 year posttransplantation were higher risk factors for L-PTDM. Impaired insulin secretion rather than insulin resistance was significantly associated with the development of P- and L-PTDM.

CONCLUSIONS

Impaired insulin secretion may be the main mechanism for the development of PTDM. Older age at transplantation seems to be associated with P-PTDM, whereas a high BMI and IFG at 1 year after transplantation were associated with L-PTDM.

Change in pancreatic B-cell function (HOMA-B) varies in different populations with similar genetic backgrounds but different environments

OBJECTIVE

To determine whether pancreatic B-cell function varies in different populations with similar genetic backgrounds but different environments.

RESEARCH DESIGN/METHODS

We compared a specific migrant Gujarati community in the UK (n = 205) with people still resident in the same villages of origin in Gujarat, India (n = 246). Pancreatic B-cell function (HOMA-B) was determined and the influence of age, migration and other factors was explored.

RESULTS

As anticipated, there was an age-related decline in log(HOMA-B) in both groups. However, the age-related fall in log(HOMA-B) was more pronounced in the UK than in Gujarat (normalized beta-0.29 vs. -0.14, P for difference = 0.03). The decline of HOMA-B with age persisted after adjustment for body mass index (UK beta = -0.31; Gujarat beta = -0.16, P = 0.015, P < 0.001). There was no significant change in insulin sensitivity (HOMA-S) with age at either site, although insulin sensitivity was lower in the UK. Fasting non-estrified fatty acid (NEFA) levels rose with age in the UK but not in Gujarat (P = 0.003 for difference in gradients). In multiple linear regression analysis, lower log(HOMA-B) was independently associated with higher fasting log(NEFA) levels; normalized beta = -0.24, P < 0.001, age; beta = -0.16, P = 0.005, higher log(insulin-like growth factor binding protein-1); beta = -0.19, P = 0.007 and lower body mass index; beta = 0.26, P = 0.001. This model accounted for 25% of the variability in HOMA-B.

CONCLUSIONS

HOMA-B as a measure of B-cell function declines more rapidly with age in the migrant UK group than in Gujarat. This may be a direct consequence of chronically higher NEFA exposure in the UK group.

Brain white matter hyperintensities: relative importance of vascular risk factors in nondemented elderly people

PURPOSE

To prospectively determine whether there is an association between brain white matter signal hyperintensities on magnetic resonance (MR) images and potential risk factors for cerebral ischemia in a well-characterized narrow age cohort of nondemented community-dwelling elderly people.

MATERIALS AND METHODS

The study population consisted of surviving members of the Aberdeen 1921 Birth Cohort, a subsample of participants in the 1932 Scottish Mental Survey who were born in 1921. With the permission of the local ethics committee and with informed written consent, 106 nondemented subjects (62 men, 44 women) aged 78-79 years underwent T2-weighted brain MR imaging. Brain MR images were scored semiquantitatively for deep white matter hyperintensities and periventricular hyperintensities. Vascular risk factors and clinical measures potentially associated with cerebral ischemia included hypertension, diabetes, cerebrovascular disease, smoking, body mass index grade, respiratory function levels (forced expiratory volume in 1 second [FEV1], forced vital capacity [FVC], and peak expiratory flow rate [PEFR]) normalized for subject's height, plasma lipid levels (cholesterol, triglycerides, high-density lipoprotein, and low-density lipoprotein), glycated hemoglobin level, and mean fasting blood glucose level. Pearson correlation coefficients were calculated for correlations between potential vascular risk factors and scores for deep white matter and periventricular hyperintensities, and stepwise multiple linear regression analysis was performed for factors with a statistically significant correlation.

RESULTS

Significant Pearson correlations with deep white matter hyperintensities were found for glycated hemoglobin level (r = 0.31), hypertension (r = 0.27), normalized FEV1 (r = -0.27), normalized FVC (r = -0.22), normalized PEFR (r = -0.27), low-density lipoprotein (r = 0.24), and cholesterol (r = 0.20), and with periventricular hyperintensities for glycated hemoglobin level (r = 0.28) and normalized PEFR (r = -0.23). Multiple linear regression analysis showed that glycated hemoglobin level and hypertension were predictive of 16.2% of the variance in deep white matter hyperintensities. When subjects with non-insulin-dependent (type 2) diabetes mellitus (n = 11) were excluded, hypertension and decreased normalized PEFR were predictive of 11.7% of the variance.

CONCLUSION

White matter hyperintensities are associated with elevated levels of glycated hemoglobin in nondemented community-dwelling elderly subjects. Hypertension and decreased normalized PEFR are the principal predictors of deep white matter hyperintensities in nondiabetic subjects.

Six-year follow-up of pancreatic β cell function in adults with latent autoimmune diabetes

AIM: To investigate the characteristics of the progression of islet β cell function in Chinese latent autoimmune diabetes in adult (LADA) patients with glutamic acid decarboxylase antibody (GAD-Ab) positivity, and to explore the prognostic factors for β cell function.

METHODS: Forty-five LADA patients with GAD-Ab positivity screened from phenotypic type 2 diabetic (T2DM) patients and 45 T2DM patients without GAD-Ab matched as controls were followed-up every 6 mo. Sixteen patients in LADA1 and T2DM1 groups respectively have been followed-up for 6 years, while 29 patients in LADA2 and T2DM2 groups respectively for only 1.5 years. GAD-Ab was determined by radioligand assay, and C-peptides (CP) by radioimmune assay.

RESULTS: The percentage of patients whose fasting CP (FCP) decreased more than 50% compared with the baseline reached to 25.0% at 1.5^th year in LADA1 group, and FCP level decreased (395.8±71.5 vs 572.8±72.3 pmol/L, P<0.05) at 2.5^th year and continuously went down to the end of follow-up. No significant changes of the above parameters were found in T2DM1 group. The average decreased percentages of FCP per year in LADA and T2DM patients were 15.8% (4.0-91.0%) and 5.2% (-3.5 to 35.5%, P = 0.000) respectively. The index of GAD-Ab was negatively correlated with the FCP in LADA patients (r_s = -0.483, P = 0.000). The decreased percentage of FCP per year in LADA patients were correlated with GAD-Ab index, body mass index (BMI) and age at onset (r_s = 0.408, -0.301 and -0.523 respectively, P<0.05). Moreover, GAD-Ab was the only risk factor for predicting β cell failure in LADA patients (B = 1.455, EXP (B) = 4.283, P = 0.023).

CONCLUSION: The decreasing rate of islet β cell function in LADA, being highly heterogeneous, is three times that of T2DM patients. The titer of GAD-Ab is an important predictor for the progression of islet β cell function, and age at onset and BMI could also act as the predictors.

Gender-dependent effect of ageing on peripheral insulin action

The aim of the present study was to investigate the effect of both gender and age on insulin secretion, peripheral insulin effectiveness and insulin-receptor binding. Eighty healthy volunteers, 40 females of mean age 38.47 +/- 11.37 years and mean BMI 21.99 +/- 2.06 kg/m(2) and 40 males of mean age 34.87 +/- 11.22 years and mean BMI 22.65 +/- 2.31 kg/m(2), with normal glucose tolerance participated in the study. Peripheral insulin effectiveness was measured by the artificial endocrine pancreas, using the euglycaemic hyperinsulinaemic clamp technique and insulin-receptor binding on circulating mononuclear blood cells. Peripheral insulin sensitivity was significantly higher in females as compared to males (p < 0.001), while males demonstrated higher total number of insulin receptors (p < 0.0001) and number of high-affinity receptors (p < 0.01). Peripheral insulin sensitivity decreased with ageing in both males and females, the reduction in females being more pronounced (p < 0.05). In the group under 40 years, the females demonstrated significantly higher insulin sensitivity as compared to males (p < 0.001) and lower insulin-receptor binding. Over 40 years, females presented higher peripheral insulin sensitivity and higher insulin-receptor binding. The percentage of specifically bound insulin increased significantly with ageing in females and decreased in males. We consider that probably the higher androgen level in males affects the post-receptor processes in insulin action and despite the higher insulin-receptor binding, males have lower insulin sensitivity. The androgen levels in females increase with ageing, which could probably affect peripheral insulin sensitivity at the post-receptor level. In conclusion, our results demonstrate that when analysing peripheral insulin effectiveness and insulin-receptor binding, one should always consider both gender and age.