A latent class model for competing risks.

Survival data analysis becomes complex when the proportional hazards assumption is violated at population level or when crude hazard rates are no longer estimators of marginal ones. We develop a Bayesian survival analysis method to deal with these situations, on the basis of assuming that the complexities are induced by latent cohort or disease heterogeneity that is not captured by covariates and that proportional hazards hold at the level of individuals. This leads to a description from which risk-specific marginal hazard rates and survival functions are fully accessible, 'decontaminated' of the effects of informative censoring, and which includes Cox, random effects and latent class models as special cases. Simulated data confirm that our approach can map a cohort's substructure and remove heterogeneity-induced informative censoring effects. Application to data from the Uppsala Longitudinal Study of Adult Men cohort leads to plausible alternative explanations for previous counter-intuitive inferences on prostate cancer. The importance of managing cardiovascular disease as a comorbidity in women diagnosed with breast cancer is suggested on application to data from the Swedish Apolipoprotein Mortality Risk Study. Copyright © 2017 John Wiley & Sons, Ltd.

Level of physical activity associated with risk of cardiovascular diseases and mortality in patients with type-2 diabetes: report from the Swedish National Diabetes Register.

AIMS: To estimate risks of coronary heart disease (CHD), cardiovascular disease (CVD), and total mortality with low or higher levels of physical activity (PA) assessed with questionnaire, in an observational study of patients with type-2 diabetes from the Swedish National Diabetes Register. SUBJECTS AND METHODS: A total of 15,462 patients (60 years), were followed for 5 years from baseline in 2004 until 2009, with 760 CVD events and 427 total mortality events based on 54,344 person-years. RESULTS: Comparing 6963 patients with low baseline PA (never or 1-2 times/week for 30 min) and 8499 patients with higher baseline PA (regular 3 times/week or more), hazard ratios for fatal/nonfatal CHD, fatal/nonfatal CVD, fatal CVD, and total mortality were 1.25 (95% CI 1.05-1.48; p = 0.01), 1.26 (95% CI 1.09-1.45; p = 0.002), 1.69 (95% CI 1.18-2.41; p = 0.004), and 1.48 (95% CI 1.22-1.79; p < 0.001), adjusting for age, sex, diabetes duration, diabetes treatment, and smoking (model 1). Adjusting also for HbA1c, systolic blood pressure, low- and high-density lipoprotein cholesterol, triglycerides, body mass index, and albuminuria (model 2), HRs were 1.19 (95% CI 1.00-1.42; p = 0.049), 1.18 (95% CI 1.02-1.36; p = 0.04), 1.54 (95% CI 1.07-2.22; p = 0.02), and 1.41 (95% CI 1.16-1.72; p < 0.001), respectively. Corresponding results (model 2), comparing 4166 patients having low PA both baseline and at follow up with all other 11,296 patients were 1.68 (95% CI 1.41-2.01), 1.68 (95% CI 1.45-1.96), 2.12 (95% CI 1.48-3.03), and 2.03 (95% CI 1.66-2.48) (all p < 0.001) and compared to 2797 patients with low baseline PA and higher PA at follow up were 2.51 (95% CI 1.87-3.38), 2.54 (95% CI 1.98-3.27), 3.26 (95% CI 1.74-6.10), and 2.91 (95% CI 2.08-4.07) (all p < 0.001). CONCLUSIONS: This large observational study of patients with type-2 diabetes showed considerably increased risks for CVD and mortality with low PA.

Anti-androgen prescribing patterns, patient treatment adherence and influencing factors; results from the nationwide PCBaSe Sweden.

PURPOSE: Adherence has not been studied in male oncology populations. The aim of this study on both the prescriber and user perspectives in prostate cancer treatment was to analyse real-life prescribing patterns of anti-androgens (AA), primarily bicalutamide, and factors influencing the patients' adherence to treatment. METHODS: A nationwide clinical cohort of incident prostate cancer, PCBaSe, was linked to the Swedish Prescribed Drug Register. Men with a planned first line monotherapy AA treatment were identified; dosages and extent of off-label treatment were investigated. Cumulative incidence proportions for reasons for drug discontinuation were calculated. Factors potentially influencing adherence were explored using the medical possession ratio based on the individual prescribed daily dose. RESULTS: First line monotherapy AA was planned in 4.4 % of all incident cases and in 2.1 % of low risk disease cases. Among 1,406 men prescribed bicalutamide, 1,109 (79 %) received the approved daily dose of 150 mg. Discontinuation reasons differed with disease severity. Off-label, low-dose prescription associated with age above 75 years and disease categorised as low risk was noted in 297 men (21 %). Sixty percent of the men adhered well, i.e. to ≥80 %. Age above 75 years and less severe disease were both negatively associated with adherence. CONCLUSIONS: Patient age and tumour risk group influenced the prescriber's choice of dose, pointing to important issues for critical reflection. Possible over-treatment was noted in low risk disease. Interventions to increase adherence in older men and in men with less severe disease are worth considering after critically reviewing the appropriateness of the treatment indication, especially in the latter case.

Relationship between body mass index and mortality among Europeans.

BACKGROUND/OBJECTIVES: To investigate the relationship between body mass index (BMI) and mortality from various causes. SUBJECTS/METHODS: Data of 72,947 European men and 62,798 women aged 24-99 years at baseline were collaboratively analyzed. Both absolute and relative mortality risks were estimated within each BMI categories. The hazard ratio was estimated using Cox regression analysis adjusting for age, cohort and smoking status. RESULTS: Over a median follow-up of 16.8 years, 29,071 participants died, 13,502 from cardiovascular disease (CVD) and 8748 from cancers of all types. All-cause and cancer mortality showed a U-shaped relationship: decreased first, leveled off, and then increased with increasing BMI with the lowest mortality risk approximately between 23.0 and 28.0 kg/m(2) of BMI in men and 21.0 and 28.0 kg/m(2) in women. The U-shaped relationship held for all-cause mortality but disappeared for cancer mortality among non-smokers. The CVD mortality was constant until a BMI of approximately 28.0 kg/m(2) and then increased gradually in both men and women, which was independent of age, cohort and smoking status. CONCLUSIONS: A U-shaped relationship of BMI with all-cause mortality but a graded relationship with CVD mortality at BMI >28.0 kg/m(2) was detected. The relationship between cancer mortality and BMI largely depended on smoking status, and need to be further investigated with site-specific cancers.

Diabetes, prediabetes and cancer mortality.

AIMS/HYPOTHESIS: We aimed to investigate the risk of cancer mortality in relation to the glucose tolerance status classified according to the 2 h OGTT. METHODS: Data from 17 European population-based or occupational cohorts involved in the DECODE study comprising 26,460 men and 18,195 women aged 25-90 years were collaboratively analysed. The cohorts were recruited between 1966 and 2004 and followed for 5.9 to 36.8 years. Cox proportional hazards analysis with adjustment for cohort, age, BMI, total cholesterol, blood pressure and smoking status was used to estimate HRs for cancer mortality. RESULTS: Compared with people in the normal glucose category, multivariable adjusted HRs (95% CI) for cancer mortality were 1.13 (1.00, 1.28), 1.27 (1.02, 1.57) and 1.71 (1.35, 2.17) in men with prediabetes, previously undiagnosed diabetes and known diabetes, respectively; in women they were 1.11 (0.94, 1.30), 1.31 (1.00, 1.70) and 1.43 (1.01, 2.02), respectively. Significant increases in deaths from cancer of the stomach, colon-rectum and liver in men with prediabetes and diabetes, and deaths from cancers of the liver and pancreas in women with diabetes were also observed. In individuals without known diabetes, the HR (95% CI) for cancer mortality corresponding to a one standard deviation increase in fasting plasma glucose was 1.06 (1.02, 1.09) and in 2 h plasma glucose was 1.07 (1.03, 1.11). CONCLUSIONS/INTERPRETATION: Diabetes and prediabetes were associated with an increased risk of cancer death, particularly death from liver cancer. Mortality from all cancers rose linearly with increasing glucose concentrations.

Vasoreactivity is rapidly improved in obese subjects after gastric bypass surgery.

BACKGROUND: Obesity is associated with increased risk of cardiovascular disease. We investigated vasoreactivity in conduit and resistance arteries in morbidly obese subjects, and the effect of weight loss after gastric bypass surgery. METHODS: A total of 19 obese subjects (body mass index (BMI): 43.8+/-3.1 kg m(-2), 75% female, mean age 41 years) were investigated before surgery and after 1 and 12 months of surgery. Nineteen non-obese controls matched for age and gender were examined. Vasoreactivity was evaluated by ultrasound to measure flow-mediated dilation (FMD, evaluating a conduit vessel) and pulse-wave analysis with terbutaline provocation (change in reflectance index (RI), evaluating resistance vessels). RESULTS: Before surgery, the obese showed a low change in RI (18+/-12 vs 37+/-15% in controls, P=0.0001), but not significantly regarding FMD (7.9+/-6.4 vs 8.9+/-5.4% in controls). Surgery resulted in a weight loss of 9% at 1 month and 30% at 1 year. Change in RI markedly improved to 36+/-12% at 1 month (P=0.0001 vs baseline) and further to 44+/-11% at 1 year (P=0.014 vs 1 month). FMD did not change significantly. Heart rate and brachial artery diameter were reduced, with no significant change in blood pressure. The improvement in resistance vessel vasodilation, estimated as change in RI, was not correlated to changes in weight or measures of glucose and lipid metabolism. CONCLUSIONS: Obese patients showed impaired vasoreactivity in resistance arteries that was normalized already 1 month after gastric bypass surgery. The basis for this remarkable outcome, not significantly related to changes in body weight and metabolic variables, remains to be clarified.

Glucose metabolism and the risk of Alzheimer's disease and dementia: a population-based 12 year follow-up study in 71-year-old men.

AIMS/HYPOTHESIS: Accumulating evidence suggests that diabetes increases the risk of dementia, but few studies have addressed possible mechanisms underlying this relationship. The aim of our study was to investigate the longitudinal association of glucose metabolism, insulin secretion and insulin action with the development of Alzheimer's disease and vascular dementia. METHODS: The Uppsala Longitudinal Study of Adult Men is an ongoing observational study in Sweden in which 1,125 men aged 71 years and free from dementia underwent an OGTT and a euglycaemic insulin clamp between 1990 and 1995. During a median follow-up of 12 years, 257 persons developed dementia or cognitive impairment, of whom 81 had Alzheimer's disease and 26 vascular dementia. Associations were analysed with the Cox proportional hazards method. RESULTS: Low early insulin response to oral glucose challenge, but not low insulin sensitivity, was associated with a higher risk of Alzheimer's disease (HR for 1 SD decrease 1.32; 95% CI 1.02, 1.69) after adjustment for diabetes, blood pressure, body mass index, cholesterol, smoking and educational level. Low insulin sensitivity was associated with a higher risk of vascular dementia (HR for 1 SD decrease 1.55; 95% CI 1.02, 2.35), but not after multiple adjustments. Diabetes increased the risk of any dementia and cognitive impairment by 63%. CONCLUSIONS/INTERPRETATION: In this community-based study, low early insulin response was associated with increased risk of subsequent Alzheimer's disease, whereas low insulin sensitivity was not. Vascular dementia was not related to early insulin response. We suggest that glucometabolic disturbances are linked differentially to the pathogenesis of these two main dementia subtypes.

Insulin sensitivity measured by the euglycaemic insulin clamp and proinsulin levels as predictors of stroke in elderly men.

AIMS/HYPOTHESIS: Our aim was to investigate the predictive power of a panel of variables in glucose and insulin metabolism for the incidence of stroke or transient ischaemic attacks (TIA). We hypothesised that proinsulin and insulin resistance contributes to an increase of risk for fatal and non-fatal stroke/TIA, independently of diabetes and established risk factors. METHODS: The study is based on the Uppsala Longitudinal Study of Adult Men cohort. The examinations were performed at age 70 years. RESULTS: In 1,151 men free from stroke at baseline, 150 developed stroke or TIA during a median follow-up of 8.8 years. In unadjusted Cox proportional hazards analyses, a 1 SD increase of a predictor variable was associated with an increased risk for stroke/TIA, e.g. plasma insulin (HR 1.19, 95% CI 1.01-1.40), fasting intact proinsulin (HR 1.28, 95% CI 1.09-1.49); whereas a 1 SD increase in insulin sensitivity measured by the euglycaemic insulin clamp method decreased the risk for stroke/TIA (HR 0.81, 95% CI 0.68-0.96). The predictive values of fasting intact proinsulin and insulin sensitivity endured but not that of plasma insulin when adjusting for diabetes. In models adjusting for diabetes, hypertension, atrial fibrillation, electrocardiographic left ventricular hypertrophy, serum cholesterol and smoking, proinsulin remained as a significant predictor of later stroke/TIA (HR 1.22, 95% CI 1.00-1.48) whereas clamp insulin sensitivity did not (HR 0.87, 95% CI 0.71-1.07). CONCLUSIONS/INTERPRETATION: Fasting intact proinsulin level and insulin sensitivity at clamp predicted subsequent fatal and non-fatal stroke/TIA, independently of diabetes in elderly men whereas fasting insulin did not.

Risk of cardiovascular disease and mortality in overweight and obese patients with type 2 diabetes: an observational study in 13,087 patients.

AIMS/HYPOTHESIS: The aim of this study of type 2 diabetic patients in the Swedish National Diabetes Register was to study the associations of BMI, overweight (BMI 25-29.9 kg/m(2)) and obesity (BMI >or= 30 kg/m(2)) with cardiovascular disease in type 2 diabetes, as these associations have not previously been clarified. METHODS: Patients aged 30-74 years with no previous CHD or stroke (N = 13,087) were followed for a mean of 5.6 years until 2003 for fatal or non-fatal CHD, stroke, cardiovascular disease (CHD or stroke) and total mortality. In total, 1,922 cardiovascular-disease events occurred, based on 64,864 person-years. RESULTS: The relative risks of CHD, stroke, cardiovascular disease and total mortality for a 5 unit increase in BMI at baseline were 15%, 11%, 13% and 27%, respectively, using Cox regression analysis, after adjusting for age, sex, diabetes duration, hypoglycaemic treatment and smoking (model 1), and were 9%, 4% (not significant), 7% and 20%, respectively, when adjusting also for HbA(1c), blood pressure, antihypertensive drugs, lipid-reducing drugs and microalbuminuria (model 2). Adjusted hazard ratios (model 1) for CHD, cardiovascular disease and total mortality with overweight were 1.27 (95% CI 1.09-1.48), 1.24 (1.09-1.41) and 1.16 (0.94-1.45), respectively, and 1.49 (1.27-1.76), 1.44 (1.26-1.64) and 1.71 (1.36-2.14) with obesity, as compared with normal weight. Significant hazard ratios were attenuated when adjusted according to model 2. For a 1 unit increase in BMI during follow-up, the relative risk of CHD (model 2) was 1.13 (1.04-1.23; p = 0.005). CONCLUSIONS/INTERPRETATION: Both overweight and obesity independently increased the risk of CHD and cardiovascular disease in patients with type 2 diabetes. The CHD risk was higher with increasing BMI than with stable or decreasing BMI during the study.

Serum and dietary beta-carotene and alpha-tocopherol and incidence of type 2 diabetes mellitus in a community-based study of Swedish men: report from the Uppsala Longitudinal Study of Adult Men (ULSAM) study.

AIMS/HYPOTHESIS: To investigate the association of serum concentrations and dietary intake of beta-carotene and alpha-tocopherol with type 2 diabetes incidence. METHODS: Serum beta-carotene, alpha-tocopherol, lifestyle factors (BMI, physical activity and smoking) and metabolic factors (insulin sensitivity [homeostasis model assessment], acute insulin response and impaired fasting glucose) were analysed in 846 50-year-old non-diabetic Swedish men (participants in the Uppsala Longitudinal Study of Adult Men). Diabetes was identified in 245 participants at reinvestigations after 10, 20 and 27 years. At the 20 year reinvestigation, dietary intake of beta-carotene and alpha-tocopherol, insulin sensitivity (euglycaemic-hyperinsulinaemic clamp) and insulin secretion (early insulin response in OGTT) were determined. RESULTS: The highest tertile of serum beta-carotene at age 50 (>0.335 mumol/l) was associated with 59% lower risk of diabetes during follow-up compared with the lowest tertile (<0.210 mumol/l) after adjustment for lifestyle and metabolic factors (p < 0.01). The highest tertile of lipid-corrected serum alpha-tocopherol at age 50 (>3.67 mumol/mmol) was associated with 46% lower risk of diabetes compared with the lowest tertile (<3.25 mumol/mmol) independently of metabolic factors (p < 0.05). Moreover, lower serum beta-carotene and alpha-tocopherol concentrations were independently associated with impaired insulin sensitivity (p < 0.001), but not with early insulin response, in a subsample of non-diabetic individuals 20 years later. Dietary intake of beta-carotene and alpha-tocopherol independently predicted type 2 diabetes during 7 years of follow-up. CONCLUSIONS/INTERPRETATION: Serum concentrations and dietary intakes of beta-carotene and alpha-tocopherol independently predicted insulin resistance and type 2 diabetes incidence during 27 years of follow-up in a community-based study of men. This result supports the importance of impaired antioxidant status for the development of insulin resistance and type 2 diabetes.

Serum cystatin C and the risk of Alzheimer disease in elderly men.

BACKGROUND: Multiple lines of research suggest that increased cystatin C activity in the brain protects against the development of Alzheimer disease (AD). METHODS: Serum cystatin C levels were analyzed at two examinations of the Uppsala Longitudinal Study of Adult Men, a longitudinal, community-based study of elderly men (age 70 years, n = 1,153 and age 77 years, n = 761, a subset of the age 70 examination). Cox regressions were used to examine associations between serum cystatin C and incident AD. AD cases were identified by cognitive screening and comprehensive medical chart review in all subjects. RESULTS: On follow-up (median 11.3 years), 82 subjects developed AD. At age 70 years, lower cystatin C was associated with higher risk of AD independently of age, APOE4 genotype, glomerular filtration rate, diabetes, hypertension, stroke, cholesterol, body mass index, smoking, education level, and plasma amyloid-beta protein 40 and 42 levels (hazard ratio [HR] for lowest [<1.12 micromol/L] vs highest [>1.30 micromol/L] tertile = 2.67, 95% CI 1.22-5.83, p < 0.02). The results were similar at age 77 years (43 participants developed AD during follow-up). Furthermore, a 0.1-mumol/L decrease of cystatin C between ages 70 and 77 years was associated with a 29% higher risk of incident AD (HR 1.29, 95% CI 1.03-1.63, p < 0.03). CONCLUSIONS: Low levels of serum cystatin C precede clinically manifest Alzheimer disease (AD) in elderly men free of dementia at baseline and may be a marker of future risk of AD. These findings strengthen the evidence for a role for cystatin C in the development of clinical AD.

Postprandial changes in gut regulatory peptides in gastric bypass patients.

OBJECTIVE: The marked weight loss induced by Roux-en-Y gastric bypass (RYGBP) for morbid obesity is still incompletely understood. It has been suggested that, besides the restriction imposed by the surgical procedure, alterations in gut regulatory peptides signaling the brain might contribute. The aim of this study was to measure the putative satiety peptides peptide YY (PYY), glucagon-like peptide-1 (GLP-1), pancreatic polypeptide (PP) and pro-neurotensin (pro-NT) in response to fasting and feeding. DESIGN: The study is a cross-sectional study. After a prolonged overnight 14 h fast, a standardized mixed meal (574 kcal) was provided. Blood samples for peptide measurements were obtained before and after the meal. SUBJECTS: Forty subjects (20 males and females) were included; 10 morbidly obese; (mean age 41+/-7 years; mean BMI 44+/-3 kg/m(2)), 10 operated with RYGBP (age 45+/-5 years; BMI 35+/-6 kg/m(2)), 10 aged-matched lean (age 44+/-5 years; BMI 24+/-3 kg/m(2)) and 10 young lean subjects (age 26+/-2 years; BMI 23+/-2 kg/m(2)). MEASUREMENTS: Plasma concentrations of PYY, GLP-1, PP and pro-NT were obtained. RESULTS: PYY levels increased more in the RYGBP group than in the other groups after the test meal. GLP-1 levels rose in the RYGBP patients, with a small increase seen in the age-matched lean group. PP concentrations increased similarly in all groups postprandially. Pro-NT levels were highest in surgical patients, with no meal effect. CONCLUSION: RYGBP subjects displayed exaggerated PYY and GLP-1 responses to a standardized meal and demonstrated higher pro-NT levels both pre- and postprandially. The findings indicate that possibly the alterations in gut peptide secretion may promote weight loss after gastric bypass surgery.

Impaired insulin secretion increases the risk of Alzheimer disease.

OBJECTIVE: Subjects with diabetes are reported to have an increased risk of dementia and cognitive impairment. However, the underlying causes remain unknown. We investigated the longitudinal associations between midlife insulin secretion, glucose metabolism, and the subsequent development of Alzheimer disease (AD) and dementia. METHODS: The population-based Uppsala Longitudinal Study of Adult Men started 1970 when the 2,322 participants were 50 years old. Investigation at baseline included determinations of acute insulin response and glucose tolerance using the IV glucose tolerance test and Homeostasis Model Assessment insulin resistance index. During a median follow up of 32 years, 102 participants were diagnosed with AD, 57 with vascular dementia, and 394 with any dementia or cognitive impairment. Associations were analyzed using Cox proportional hazard models. RESULTS: A low insulin response at baseline was associated with a higher cumulative risk of AD (hazard ratio for 1 SD decrease, 1.31; 95% CI, 1.10-1.56) also after adjustment for age, systolic blood pressure, body mass index, serum cholesterol, smoking, education level, and insulin resistance. This association was stronger in subjects without the APOE epsilon4 allele. Impaired glucose tolerance increased the risk of vascular dementia (hazard ratio for 1 SD decrease, 1.45; 95% CI, 1.05-2.00) but not AD. Impaired insulin secretion, glucose intolerance, and estimates of insulin resistance were all associated with higher risk of any dementia and cognitive impairment. CONCLUSIONS: In this longitudinal study, impaired acute insulin response at midlife was associated with an increased risk of Alzheimer disease (AD) up to 35 years later suggesting a causal link between insulin metabolism and the pathogenesis of AD.

Gastric bypass alters the dynamics and metabolic effects of insulin and proinsulin secretion.

AIMS: Hyperproinsulinaemia is associated with obesity and is a risk factor for Type 2 diabetes. We explored the dynamics of proinsulin and insulin and postprandial effects on glucose and lipids in subjects who had undergone gastric bypass (GBP) surgery compared with morbidly obese (MO) subjects and normal weight control subjects (NW). METHODS: Subjects free from diabetes were recruited: 10 previously MO subjects [body mass index (BMI) +/- sd, 34.8 +/- 6.2 kg/m2] who had undergone GBP surgery, 10 MO subjects (BMI 44 +/- 3.1 kg/m2) and 12 NW control subjects (BMI 23.2 +/- 2.4 kg/m2). After an overnight fast, a standard meal (2400 kJ) was ingested and glucose, proinsulin, insulin free fatty acids and triglycerides were determined up to 180 min. RESULTS: Fasting proinsulin was similar in the GBP group and NW control subjects, but threefold increased in MO subjects (P < 0.05). Postprandial AUC for glucose was similar in the three groups and AUC for proinsulin was high in MO, intermediate in the GBP group and lowest in NW control subjects (P for trend = 0.020). Postprandial proinsulin at 60 min was similar in the GBP group and MO subjects and twofold higher than in NW control subjects. Postprandial proinsulin at 180 min was normal in the GBP group, but fivefold increased in MO subjects (P = 0.008). Insulin increased rapidly at 30 min in the GBP group and was normal at 90 min, whereas insulin was still increased at 90-180 min in the MO subjects (P < 0.001). CONCLUSIONS: MO subjects, free from diabetes, have elevated proinsulin concentrations in the fasting as well as the postprandial phase. After GBP surgery markedly lower fasting and postprandial proinsulin concentrations were observed, although BMI was higher compared with NW control subjects.

Insulin sensitivity, proinsulin and insulin as predictors of coronary heart disease. A population-based 10-year, follow-up study in 70-year old men using the euglycaemic insulin clamp.

AIMS/HYPOTHESIS: The association between CHD and insulin sensitivity (Si) measured by the euglycaemic insulin clamp has not been examined previously. Earlier studies found a relationship between CHD and elevated plasma insulin, an analysis that may have been confounded by co-determination of proinsulin, which has evolved as a stronger predictor of CHD. The aim was to determine the longitudinal relationships between Si, intact proinsulin, 32-33 split proinsulin, specific insulin and subsequent CHD. METHODS: This was a population-based cohort study of 815 men in Uppsala, Sweden, aged 70 years at baseline with a follow-up of up to 10 years. Baseline insulin sensitivity was determined by euglycaemic insulin clamp. Fasting proinsulin, 32-33 split proinsulin and specific insulin concentrations were analysed using specific two-site immunometric assays. CHD was taken as diagnosed, if stated (in the event of death) on the Cause of Death Registry, or for subjects hospitalised for the first time with CHD, if CHD was recorded in the Hospital-Discharge Registry. The associations were analysed using Cox's proportional hazards, presented as hazard ratios (HRs) with their 95% CIs for a one-SD increase in the predictor. RESULTS: In multivariate analysis, Si (HR:0.80, CI:0.65-0.97) adjusted for serum cholesterol, systolic blood pressure, fasting plasma glucose, BMI and smoking predicted CHD. Intact proinsulin (HR:1.18, CI:1.01-1.38), adjusted as the model above, predicted CHD, whereas 32-33 split proinsulin (HR:1.13, CI:0.95-1.35) or specific insulin (HR:1.07, CI:0.89-1.30) did not. CONCLUSIONS/INTERPRETATION: Insulin resistance measured by the euglycaemic insulin clamp predicts subsequent CHD in elderly men. Proinsulin provides a better prediction of CHD than insulin.

Impaired insulin sensitivity is an independent predictor of common carotid intima-media thickness in a population sample of elderly men.

Most previous studies of associations between insulin sensitivity and common carotid artery (CCA) atherosclerosis have been conducted in small samples, have not used direct measurement of insulin sensitivity, and have yielded inconclusive results. We investigated associations of CCA intima-media thickness (IMT) and diameter (CCA-D) measured by B-mode ultrasound and insulin sensitivity measured by the euglycemic hyperinsulinemic clamp test together with risk factors of the insulin resistance syndrome in a community-based sample of 493 elderly men. The clamp glucose disposal rate was an independent predictor of CCA-IMT in multivariate models adjusting for blood pressure, smoking, serum cholesterol, and body mass index (1% decrease in CCA-IMT for a 1 unit increase in glucose disposal rate, P=0.009). Glucose disposal rate was significantly related to CCA-D in univariate (r=-0.11, P=0.02) but not in multivariate models. In conclusion, this study is the first to establish impaired insulin sensitivity, measured by the euglycemic hyperinsulinemic clamp test, as an independent predictor of CCA-IMT in a population-based sample of elderly men.

In vitro and in vivo studies of a naturally occurring variant of the human p85alpha regulatory subunit of the phosphoinositide 3-kinase: inhibition of protein kinase B and relationships with type 2 diabetes, insulin secretion, glucose disappearance constant, and insulin sensitivity.

In humans, the Met326Ile missense variant of the p85alpha regulatory subunit of the phosphoinositide 3-kinase (PI3K) has been associated with either significant reductions in glucose effectiveness and intravenous glucose tolerance in Caucasians or a significantly higher insulin secretory response in Pima Indians. In the present study, we genotyped 1,190 Caucasian males to evaluate the impact in vivo of the Met326Ile variant of the p85alpha subunit of PI3K on the acute insulin response, intravenous glucose tolerance, insulin-mediated glucose uptake, and the prevalence of type 2 diabetes after 20 years of follow-up. We also expressed the variant in vitro to evaluate the impact on insulin-stimulated activation of protein kinase B (PKB). The Met326Ile variant of p85alpha was not associated with type 2 diabetes or with alterations in insulin secretion, insulin sensitivity, or intravenous glucose tolerance in vivo. Expressed in vitro, the Ile326 and the Met326 variant acted equally as a dominant-negative and prevented (60-70% inhibition) insulin-mediated activation of PKB by inhibiting the phosphorylation of PKB at Thr308. We conclude that the Met326Ile variant of the p85alpha regulatory subunit of PI3K is likely to be as functionally normal in vivo as in vitro.