Diabetes and aging: epidemiologic overview

The Effect of Parathyroid Hormone on Osseointegration in Insulin-Treated Diabetic Rats

OBJECTIVES

Uncontrolled diabetes mellitus is associated with impaired osseointegration. Diabetic individuals might benefit from bone anabolic therapies. Intermittent administration of 1-34 parathyroid hormone (PTH) stimulates bone formation in rodent models. However, this anabolic effect fails in diabetic rats. Whether the anabolic effect of PTH can be achieved in insulin-controlled diabetic rats has not been investigated yet.

MATERIALS AND METHODS

After diabetes induction with streptozotocin in 40 female Wistar rats, the animals were randomly divided into 4 groups: diabetes, diabetes plus PTH, insulin-treated diabetes, and insulin-treated diabetes plus PTH. After 1 week, miniscrews were inserted in the tibiae. Osmotic pumps with insulin or saline solution were implanted. Animals received 60 mg/kg PTH or saline solution. Histomorphometric analysis was performed.

RESULTS

In diabetic rats, no changes of medullary periimplant bone area or bone-to-implant contacts (BICs) were achieved with or without treatment with PTH. However, also animals treated with insulin failed to response significantly to PTH regarding bone area (7.4 ± 4.1% and 8.1 ± 4.1%) and BICs (33.7 ± 16.9% and 49.9 ± 11.9%).

CONCLUSION

These results demonstrate that the metabolic characteristics of the diabetic rats produced a condition unable to respond to PTH treatment, even when hyperglycemia was controlled with insulin.

Reverse geroscience: how does exposure to early diseases accelerate the age-related decline in health?

Aging is the major risk factor for both the development of chronic diseases and loss of functional capacity. Geroscience provides links among the biology of aging, the biology of disease, and the physiology of frailty, three fields where enormous progress has been made in the last few decades. While, previously, the focus was on the role of aging in susceptibility to disease and disability, the other side of this relationship, which is the contribution of disease to aging, has been less explored at the molecular/cellular level. Indeed, the role of childhood or early adulthood exposure to chronic disease and/or treatment on accelerating aging phenotypes is well known in epidemiology, but the biological basis is poorly understood. A recent summit co-organized by the National Institutes of Health GeroScience Interest Group and the New York Academy of Sciences explored these relationships, using three chronic diseases as examples: cancer, HIV/AIDS, and diabetes. The epidemiological literature clearly indicates that early exposure to any of these diseases and/or their treatments results in an acceleration of the appearance of aging phenotypes, including loss of functional capacity and accelerated appearance of clinical symptoms of aging-related diseases not obviously related to the earlier event. The discussions at the summit focused on the molecular and cellular relationships between each of these diseases and the recently defined molecular and cellular pillars of aging. Two major conclusions from the meeting include the desire to refine an operational definition of aging and to concomitantly develop biomarkers of aging, in order to move from chronological to physiological age. The discussion also opened a dialogue on the possibility of improving late-life outcomes in patients affected by chronic disease by including age-delaying modalities along with the standard care for the disease in question.

Hospitalization of elderly diabetic patients: characteristics, reasons for admission, and gender differences

Background

Understanding the differences in characteristics, gender, and common causes for admission in hospitalized elderly diabetic patients provides a theoretical basis for their successful management. This study explored the reasons and gender differences in hospitalizations of elderly patients with diabetes mellitus.

Methods

Patients aged ≥60 years who had received a diagnosis of diabetes by the time of discharge, from 1 January 2011 to 1 January 2014, were retrospectively enrolled. Hospitalization data of the patients were collected, and reasons for hospitalization were analyzed based on chief complaints and principle diagnosis.

Results

The most frequent reasons stated for admission were related to the chronic complications of diabetes (42.1 %), seconded by hyperglycemia (26.4 %) and infection (15.7 %). Ketonuria, ketonemia, or diabetic ketoacidosis was more commonly seen in women than men, whereas diabetic nephropathy and neoplasms were more frequently found in men than women. Regarding infection as a cause of hospitalization, the 4 main types were respiratory tract (44.5 %), urinary tract (20.3 %), gastrointestinal (14.8 %), and skin and soft tissue (10.9 %). Respiratory tract infection was significantly more common in men (61.4 %) than women (31 %, P = 0.001), whereas urinary tract infection was more frequent in women (29.6 %) than men (8.8 %, P = 0.004).

Conclusion

The most frequent reasons for hospital admission in elderly diabetic patients were chronic complications of diabetes, hyperglycemia, and infection. Men and women differed in reasons for hospital admission.

A call for comparative effectiveness research to learn whether routine clinical care decisions can protect from dementia and cognitive decline

Common diseases like diabetes, hypertension, and atrial fibrillation are probable risk factors for dementia, suggesting that their treatments may influence the risk and rate of cognitive and functional decline. Moreover, specific therapies and medications may affect long-term brain health through mechanisms that are independent of their primary indication. While surgery, benzodiazepines, and anti-cholinergic drugs may accelerate decline or even raise the risk of dementia, other medications act directly on the brain to potentially slow the pathology that underlies Alzheimer’s and other dementia. In other words, the functional and cognitive decline in vulnerable patients may be influenced by the choice of treatments for other medical conditions. Despite the importance of these questions, very little research is available. The Alzheimer’s Drug Discovery Foundation convened an advisory panel to discuss the existing evidence and to recommend strategies to accelerate the development of comparative effectiveness research on how choices in the clinical care of common chronic diseases may protect from cognitive decline and dementia.

A short leucocyte telomere length is associated with development of insulin resistance

AIMS/HYPOTHESIS

A number of studies have shown that leucocyte telomere length (LTL) is inversely associated with insulin resistance and type 2 diabetes mellitus. The aim of the present longitudinal cohort study, utilising a twin design, was to assess whether shorter LTL predicts insulin resistance or is a consequence thereof.

METHODS

Participants were recruited between 1997 and 2000 through the population-based national Danish Twin Registry to participate in the GEMINAKAR study, a longitudinal evaluation of metabolic disorders and cardiovascular risk factors. Baseline and follow-up measurements of LTL and insulin resistance over an average of 12 years were performed in a subset of the Registry consisting of 338 (184 monozygotic and 154 dizygotic) same-sex twin pairs.

RESULTS

Age at baseline examination was 37.4 ± 9.6 (mean ± SD) years. Baseline insulin resistance was not associated with age-dependent changes in LTL (attrition) over the follow-up period, whereas baseline LTL was associated with changes in insulin resistance during this period. The shorter the LTL at baseline, the more pronounced was the increase in insulin resistance over the follow-up period (p < 0.001); this effect was additive to that of BMI. The co-twin with the shorter baseline LTL displayed higher insulin resistance at follow-up than the co-twin with the longer LTL.

CONCLUSIONS/INTERPRETATION

These findings suggest that individuals with short LTL are more likely to develop insulin resistance later in life. By contrast, presence of insulin resistance does not accelerate LTL attrition.

Expression pattern of CYP24 in liver during ageing in long-term diabetes

Association of liver calcitriol (active vitamin D metabolite) catabolism with osteomalacia during prolonged use of certain drugs was reported in several recent studies. To examine whether the increased calcitriol catabolism could be a potential link between ageing/diabetes mellitus (DM) and bone loss, we studied the dynamic of expression of CYP24, the main calcitriol catabolising enzyme in the liver of rats during ageing and a long-term experimental DM1. DM1 model was induced with intraperitoneally injected streptozotocin (STZ) (55mg/kg). Sprague-Dawley rats were sacrificed 6 and 12 months after the DM1 induction. The immunohistochemical analyses of CYP24 and transforming growth factor β 1 (TGF-β1) expression in the liver were performed. We found that ageing and long-term DM1 resulted in a significantly increased expression of CYP24 in hepatocytes, as well as in non-hepatocyte liver cells (Kupffer cells, hepatic stellate cells and sinusoidal endothelial cells). Ageing and long-term DM1 resulted in an increased expression of TGF-β1 as well. Expression of CYP24 coexisted with the expression of TGF-β1 in all types of hepatic cells. We concluded that liver has the capacity for an active vitamin D catabolism in different populations of liver cells, especially in sinusoidal endothelial cells, through an expression of CYP24. That capacity is substantially increased during ageing and long-term diabetes mellitus. Increased liver calcitriol catabolism could be one of the mechanisms of the bone metabolism impairment related to ageing and diabetes.

Assessment of bone turnover and bone quality in type 2 diabetic bone disease: current concepts and future directions

Substantial evidence exists that in addition to the well-known complications of diabetes, increased fracture risk is an important morbidity. This risk is probably due to altered bone properties in diabetes. Circulating biochemical markers of bone turnover have been found to be decreased in type 2 diabetes (T2D) and may be predictive of fractures independently of bone mineral density (BMD). Serum sclerostin levels have been found to be increased in T2D and appear to be predictive of fracture risk independent of BMD. Bone imaging technologies, including trabecular bone score (TBS) and quantitative CT testing have revealed differences in diabetic bone as compared to non-diabetic individuals. Specifically, high resolution peripheral quantitative CT (HRpQCT) imaging has demonstrated increased cortical porosity in diabetic postmenopausal women. Other factors such as bone marrow fat saturation and advanced glycation endproduct (AGE) accumulation might also relate to bone cell function and fracture risk in diabetes. These data have increased our understanding of how T2D adversely impacts both bone metabolism and fracture risk.

The death spiral: predicting death in Drosophila cohorts

Drosophila research has identified a new feature of aging that has been called the death spiral. The death spiral is a period prior to death during which there is a decline in life-history characters, such as fecundity, as well as physiological characters. First, we review the data from the Drosophila and medfly literature that suggest the existence of death spirals. Second, we re-analyze five cases with such data from four laboratories using a generalized statistical framework, a re-analysis that strengthens the case for the salience of the death spiral phenomenon. Third, we raise the issue whether death spirals need to be taken into account in the analysis of functional characters over age, in aging research with model species as well as human data.

Frailty and geography: should these two factors be added to the ABCDE contemporary guide to diabetes therapy?

On the road towards personalized treatments for type 2 diabetes, we suggest here that two parameters could be added to the ABCDE algorithm, 'F' for frailty and 'G' for geography. Indeed, the progressive ageing of population is causing a simultaneous increase of frailty worldwide. The identification of the optimal therapeutic approach is often difficult in frail subjects because of the complexity of 'frailty syndrome'. Nevertheless, given the relevance of diabetes in the development and progression of frailty, a safe and effective cure of diabetes is extremely important to guarantee a good medical outcome. There are few data about diabetes treatment in this delicate category of patients, and the choice of the appropriate therapy mostly remains a challenge. Moreover, type 2 diabetes affects more than 382 million people of different countries, races and ethnicities. To face the lack of solid evidence-based medicine for the treatment of diabetes in different ethnic groups, it is extremely important to increase knowledge about the different pathophysiology of diabetes according to ethnicity. In this way, a tailored approach to treatment of various ethnic groups living in the same or different regions can eventually be developed. Copyright © 2016 John Wiley & Sons, Ltd.

Where frailty meets diabetes

Diabetes is a chronic illness that has an effect on multiple organ systems. Frailty is a state of increased vulnerability to stressors and a limited capacity to maintain homeostasis. It is a multidimensional concept and a dynamic condition that can improve or worsen over time. Frailty is either physical or psychological or a combination of these two components. Sarcopenia, which is the age-related loss of skeletal muscle mass and strength, is the main attributor to the physical form of frailty. Although the pathophysiology of diabetes is commonly focused on impaired insulin secretion, overload of gluconeogenesis and insulin resistance, newer insights broaden this etiologic horizon. Immunologic factors that create a chronic state of low-grade inflammation--'inflammaging'--have an influence on both the ageing process and diabetes. Persons with diabetes mellitus already tend to have an accelerated ageing process that places them at greater risk for developing frailty at an earlier age. The development of frailty--and sarcopenia--is multifactorial and includes nutritional, physical and hormonal elements; these elements are interlinked with those of diabetes. A lower muscle mass will lead to poorer glycaemic control through lower muscle glucose uptake. This leads to higher insulin secretion and insulin resistance, which is the stepping stone for diabetes itself.

Prevalence of and Risk Factors for Type 2 Diabetes Mellitus in Vietnam: A Systematic Review

This systematic review examined trends in the prevalence of type 2 diabetes mellitus (T2DM) and identified its risk factors among adults in Vietnam. PubMed, Web of Science, Wiley Online Library, and Scopus databases were searched to identify relevant literature. The search yielded 10 studies, including 2 national surveys and 8 regional investigations. National prevalence estimates of T2DM were 2.7% in 2002 and 5.4% in 2012. The estimates for the northern region were 1.4% in 1994 and 3.7% in 2012 and those for the southern region were 3.8% in 2004, 7.0% in 2008, and 12.4% in 2010. The major determinants of T2DM included older age, urban residence, high levels of body and abdominal fat, physical inactivity, sedentary lifestyle, genetic factors, and hypertension. The prevalence rate by gender was variable in both national and regional studies. There was insufficient information available on some potentially important risk factors such as smoking, dietary intake, income, and educational level. Our review signifies a rapidly growing prevalence of T2DM in Vietnam and suggests that extra effort is required to prevent and control this disease.

The role of type 2 diabetes in neurodegeneration

A growing body of evidence links type-2 diabetes (T2D) with dementia and neurodegenerative diseases such as Alzheimer's disease (AD). AD is the most common form of dementia and is characterised neuropathologically by the accumulation of extracellular beta amyloid (Aβ) peptide aggregates and intracellular hyper-phosphorylated tau protein, which are thought to drive and/or accelerate inflammatory and oxidative stress processes leading to neurodegeneration. Although the precise mechanism remains unclear, T2D can exacerbate these neurodegenerative processes. Brain atrophy, reduced cerebral glucose metabolism and CNS insulin resistance are features of both AD and T2D. Cell culture and animal studies have indicated that the early accumulation of Aβ may play a role in CNS insulin resistance and impaired insulin signalling. From the viewpoint of insulin resistance and impaired insulin signalling in the brain, these are also believed to initiate other aspects of brain injury, including inflammatory and oxidative stress processes. Here we review the clinical and experimental pieces of evidence that link these two chronic diseases of ageing, and discuss underlying mechanisms. The evaluation of treatments for the management of diabetes in preclinical, and clinical studies and trials for AD will also be discussed.

Morphological and migratory alterations in retinal Müller cells during early stages of hypoxia and oxidative stress

In the present study, retinal Müller cells were cultured in vitro and treated with hydrogen peroxide (oxidative stressor) and cobalt chloride (hypoxic injury). Following 24 hours of culture, compensatory hypertrophy was observed and cellular apoptosis increased. Hypoxia enhanced the migration ability of retinal Müller cells and induced the expression of α-smooth muscle actin. Oxidative stress altered the morphology of Müller cells when compared with hypoxia treatment.

Melatonin and diet-induced metabolic syndrome in rats: impact on the hypophysial-testicular axis

Abstract Combinations of fructose- and fat-rich diets in experimental animals can model the human metabolic syndrome (MS). In rats, the increase in blood pressure (BP) after diet manipulation is sex related and highly dependent on testosterone secretion. However, the extent of the impact of diet on rodent hypophysial-testicular axis remains undefined. In the present study, rats drinking a 10% fructose solution or fed a high-fat (35%) diet for 10 weeks had higher plasma levels of luteinizing hormone (LH) and lower plasma levels of testosterone, without significant changes in circulating follicle-stimulating hormone or the weight of most reproductive organs. Diet manipulation brought about a significant increase in body weight, systolic BP, area under the curve (AUC) of glycemia after an intraperitoneal glucose tolerance test (IPGTT), and plasma low-density lipoprotein cholesterol, cholesterol, triglycerides, and uric acid levels. The concomitant administration of melatonin (25 μg/mL of drinking water) normalized the abnormally high LH levels but did not affect the inhibited testosterone secretion found in fructose- or high-fat-fed rats. Rather, melatonin per se inhibited testosterone secretion. Melatonin significantly blunted the body weight and systolic BP increase, the increase in the AUC of glycemia after an IPGTT, and the changes in circulating lipid profile and uric acid found in both MS models. The results are compatible with a primary inhibition of testicular function in diet-induced MS in rats and with the partial effectiveness of melatonin to counteract the metabolic but not the testicular sequelae of rodent MS.

Diabetes, Obesity, and the Brain: New Developments in Biobehavioral Medicine

Diabetes and obesity, two major public health concerns, are associated with increased risk for problems in multiple organ systems, including the central nervous system. The adverse effects of diabetes and obesity on cognitive functioning are increasingly well recognized. This special issue of Psychosomatic Medicine features the latest research linking diabetes, obesity, and brain structure, function, and metabolism and follows a special meeting on this topic organized by the American Psychosomatic Society in October 2013. Evidence for the increased prevalence of diabetes and obesity is reviewed as it relates to cognitive decline. These articles indicate that the age of onset of Type 1 diabetes may be relevant to future cognitive function and that disease duration of Type 2 diabetes and sociocultural factors are related to cognitive decline during the aging process. The hypothalamus and other neural circuits, notably the dopaminergic system that underlies feeding and reward-related aspects of food intake, are among the key factors involved in obesity. Research on the associations between obesity and cognitive function is described using the positive effects of weight reduction following bariatric surgery or behavioral methods. This special issue concludes with a conceptual framework for linking obesity and diabetes with accelerated cognitive decline as related to the aging process. The collection of articles highlights the importance of using a life span perspective to understand the influence of both Type 1 and Type 2 diabetes on brain metabolism, function, and structure. Moreover, these studies show that distressing environmental circumstances can adversely influence neurocognitive dysfunction associated with obesity and diabetes.

Racial/ethnic and gender differences in severity of diabetes-related complications, health care resource use, and costs in a Medicare population

This retrospective cohort study evaluated associations of race/ethnicity and gender with outcomes of diabetes complications severity, health care resource utilization (HRU), and costs among Medicare Advantage health plan members with type 2 diabetes (T2DM). Medical and pharmacy claims were evaluated for 333,576 members continuously enrolled from January 1, 2010, to December 31, 2011, aged 18-89 years, with ≥1 primary diagnosis medical claim, or ≥2 claims with a secondary diagnosis of T2DM (International Classification of Diseases, Ninth Revision, Clinical Modification code 250.x0 or 250.x2). Complications severity assessment by Diabetes Complications Severity Index ranged from 0 (no complications) to 5+. Mean (SD) all-cause medical, pharmacy, and total costs were reported alongside all-cause HRU by place of service (outpatient, inpatient, emergency room [ER]) and number of visits. Multivariate regression showed being Hispanic, black, or male was associated with higher prevalence of more severe complications. This racial/ethnic disparity was more pronounced among females, among whom odds of having more severe complications were higher for Hispanic and black as compared to white females [(Hispanic vs. white odds ratio [OR], 1.40; 95% confidence interval [CI], 1.32-1.48), and (black vs. white OR, 1.22; 95% CI, 1.19-1.25)]. Regardless of gender, blacks had more ER visits than whites. White females incurred the highest total health care costs (mean annual costs: $13,086; 95% CI, $12,935-$13,240, vs. Hispanic females: $10,732; 95% CI, $10,406-$11,067). These effects held regardless of other demographic and clinical attributes. These findings suggest racial/ethnic and gender differences exist in certain T2DM clinical and economic outcomes.

Genome-wide DNA methylation changes in skeletal muscle between young and middle-aged pigs

BACKGROUND

Age-related physiological, biochemical and functional changes in mammalian skeletal muscle have been shown to begin at the mid-point of the lifespan. However, the underlying changes in DNA methylation that occur during this turning point of the muscle aging process have not been clarified. To explore age-related genomic methylation changes in skeletal muscle, we employed young (0.5 years old) and middle-aged (7 years old) pigs as models to survey genome-wide DNA methylation in the longissimus dorsi muscle using a methylated DNA immunoprecipitation sequencing approach.

RESULTS

We observed a tendency toward a global loss of DNA methylation in the gene-body region of the skeletal muscle of the middle-aged pigs compared with the young group. We determined the genome-wide gene expression pattern in the longissimus dorsi muscle using microarray analysis and performed a correlation analysis using DMR (differentially methylated region)-mRNA pairs, and we found a significant negative correlation between the changes in methylation levels within gene bodies and gene expression. Furthermore, we identified numerous genes that show age-related methylation changes that are potentially involved in the aging process. The methylation status of these genes was confirmed using bisulfite sequencing PCR. The genes that exhibited a hypomethylated gene body in middle-aged pigs were over-represented in various proteolysis and protein catabolic processes, suggesting an important role for these genes in age-related muscle atrophy. In addition, genes associated with tumorigenesis exhibited aged-related differences in methylation and expression levels, suggesting an increased risk of disease associated with increased age.

CONCLUSIONS

This study provides a comprehensive analysis of genome-wide DNA methylation patterns in aging pig skeletal muscle. Our findings will serve as a valuable resource in aging studies, promoting the pig as a model organism for human aging research and accelerating the development of comparative animal models in aging research.

Chinese Prescription Kangen-karyu and Salviae Miltiorrhizae Radix Improve Age-Related Oxidative Stress and Inflammatory Response through the PI3K/Akt or MAPK Pathways

This study examined whether Kangen-karyu and its crude drug, Salviae Miltiorrhizae Radix, have a reno-protective effect on the age-related oxidative stress and inflammatory response through the phosphoinositide 3-kinase (PI3K)/Akt or mitogen-activated protein kinase (MAPK) pathways in aged rats. Kangen-karyu or Salviae Miltiorrhizae Radix (20 mg/kg body weight/day) was administered orally to old groups of rats for 16 days, and their effects were compared with the vehicle-treated old and young rats. The administration of Kangen-karyu caused a slight decrease in the serum glucose level and a significant decrease in the serum insulin level in the old rats. The increased levels of serum renal functional parameter (urea-nitrogen) and oxidative parameter were significantly reduced by both Kangen-karyu and Salviae Miltiorrhizae Radix. The old rats exhibited a dysregulation of the protein expression related to insulin resistance, oxidative stress, and inflammation in the kidneys, but Kangen-karyu administration significantly reduced the expression of the inflammatory proteins through the PI3K/Akt pathway. On the other hand, the Salviae Miltiorrhizae Radix-treated old rats showed a decrease in the inflammatory cytokines through the MAPK pathway. These results provide important evidence that Kangen-karyu and Salviae Miltiorrhizae Radix have a pleiotropic effect on the PI3K/Akt and MAPK pathways, showing renoprotective effects against the development of inflammation in old rats. This study provides scientific evidence that Kangen-karyu and Salviae Miltiorrhizae Radix improve the inflammatory responses via the PI3K/Akt or MAPK pathways in the kidney of old rats.

Special Considerations for Older Adults With Diabetes Residing in Skilled Nursing Facilities

About 25% of all residents of skilled nursing facilities (SNFs) have diabetes, and that proportion is expected to increase. SNF residents with diabetes have special needs related to nutrition, hydration, physical activity, and medical therapy. Vigilant assessment and maintenance of safety is also crucial for such patients, including but not limited to issues such as hyper- and hypoglycemia, polypharmacy, falls, lower-extremity problems, and transitions of care. Interventions to provide stable glycemic control; ensure adequate nutrition, hydration, and physical activity; decrease polypharmacy; prevent falls; facilitate transitions of care; and improve the diabetes-related knowledge of SNF staff can help to meet these needs. Although this article focuses on SNFs, many of the topics covered also apply to elderly people with diabetes in other long-term care settings.

Adult Stem Cells and Diseases of Aging

Preservation of adult stem cells pools is critical for maintaining tissue homeostasis into old age. Exhaustion of adult stem cell pools as a result of deranged metabolic signaling, premature senescence as a response to oncogenic insults to the somatic genome, and other causes contribute to tissue degeneration with age. Both progeria, an extreme example of early-onset aging, and heritable longevity have provided avenues to study regulation of the aging program and its impact on adult stem cell compartments. In this review, we discuss recent findings concerning the effects of aging on stem cells, contributions of stem cells to age-related pathologies, examples of signaling pathways at work in these processes, and lessons about cellular aging gleaned from the development and refinement of cellular reprogramming technologies. We highlight emerging therapeutic approaches to manipulation of key signaling pathways corrupting or exhausting adult stem cells, as well as other approaches targeted at maintaining robust stem cell pools to extend not only lifespan but healthspan.

Developmental ORIgins of Healthy and Unhealthy AgeiNg: the role of maternal obesity--introduction to DORIAN

Europe has the highest proportion of elderly people in the world. Cardiovascular disease, type 2 diabetes, sarcopenia and cognitive decline frequently coexist in the same aged individual, sharing common early risk factors and being mutually reinforcing. Among conditions which may contribute to establish early risk factors, this review focuses on maternal obesity, since the epidemic of obesity involves an ever growing number of women of reproductive age and children, calling for appropriate studies to understand the consequences of maternal obesity on the offspring's health and for developing effective measures and policies to improve people's health before their conception and birth. Though the current knowledge suggests that the long-term impact of maternal obesity on the offspring's health may be substantial, the outcomes of maternal obesity over the lifespan have not been quantified, and the molecular changes induced by maternal obesity remain poorly characterized. We hypothesize that maternal insulin resistance and reduced placental glucocorticoid catabolism, leading to oxidative stress, may damage the DNA, either in its structure (telomere shortening) or in its function (via epigenetic changes), resulting in altered gene expression/repair, disease during life, and pathological ageing. This review illustrates the background to the EU-FP7-HEALTH-DORIAN project.

Reference values for cardiorespiratory fitness and incidence of type 2 diabetes

BACKGROUND

In "Physical Activity Reference for Health Promotion 2013" the Japan Ministry of Health, Labour and Welfare publication gives reference values for cardiorespiratory fitness (CRF) required for good health. We examined the associations between the CRF reference values and incidence of type 2 diabetes.

METHODS

This prospective cohort study enrolled 4633 nondiabetic Japanese men aged 20 to 39 years at baseline. CRF was measured using the cycle ergometer test, and maximal oxygen uptake was estimated. On the basis of the CRF reference value, participants were classified into 2 groups: those with values less than the reference value (under-RV) and those with values equal to or greater than reference value (over-RV). Hazard ratios (HRs) and 95% CIs for incident type 2 diabetes were estimated using a Cox proportional hazards model.

RESULTS

A total of 266 participants developed type 2 diabetes during the 14 years of follow-up. As compared with the under-RV group, the over-RV group had a significantly lower multivariable-adjusted HR for type 2 diabetes (HR 0.67; 95% CI, 0.51-0.89). In receiver operating characteristic analysis, the optimal CRF cut-off value for predicting incident type 2 diabetes was 10.8 metabolic equivalents (sensitivity, 0.64; specificity, 0.64), which was close to the CRF reference value of 11.0 metabolic equivalents.

CONCLUSIONS

The reference CRF value appears to be reasonably valid for prevention of type 2 diabetes, especially among Japanese men younger than 40 years. Development of type 2 diabetes can be prevented by maintaining a CRF level above the reference value.

Bone marrow fat composition as a novel imaging biomarker in postmenopausal women with prevalent fragility fractures

The goal of this magnetic resonance (MR) imaging study was to quantify vertebral bone marrow fat content and composition in diabetic and nondiabetic postmenopausal women with fragility fractures and to compare them with nonfracture controls with and without type 2 diabetes mellitus. Sixty-nine postmenopausal women (mean age 63 ± 5 years) were recruited. Thirty-six patients (47.8%) had spinal and/or peripheral fragility fractures. Seventeen fracture patients were diabetic. Thirty-three women (52.2%) were nonfracture controls. Sixteen women were diabetic nonfracture controls. To quantify vertebral bone marrow fat content and composition, patients underwent MR spectroscopy (MRS) of the lumbar spine at 3 Tesla. Bone mineral density (BMD) was determined by dual-energy X-ray absorptiometry (DXA) of the hip and lumbar spine (LS) and quantitative computed tomography (QCT) of the LS. To evaluate associations of vertebral marrow fat content and composition with spinal and/or peripheral fragility fractures and diabetes, we used linear regression models adjusted for age, race, and spine volumetric bone mineral density (vBMD) by QCT. At the LS, nondiabetic and diabetic fracture patients had lower vBMD than controls and diabetics without fractures (p = 0.018; p = 0.005). However, areal bone mineral density (aBMD) by DXA did not differ between fracture and nonfracture patients. After adjustment for age, race, and spinal vBMD, the prevalence of fragility fractures was associated with -1.7% lower unsaturation levels (confidence interval [CI] -2.8% to -0.5%, p = 0.005) and +2.9% higher saturation levels (CI 0.5% to 5.3%, p = 0.017). Diabetes was associated with -1.3% (CI -2.3% to -0.2%, p = 0.018) lower unsaturation and +3.3% (CI 1.1% to 5.4%, p = 0.004) higher saturation levels. Diabetics with fractures had the lowest marrow unsaturation and highest saturation. There were no associations of marrow fat content with diabetes or fracture. Our results suggest that altered bone marrow fat composition is linked with fragility fractures and diabetes. MRS of spinal bone marrow fat may therefore serve as a novel tool for BMD-independent fracture risk assessment.

Accelerated fat cell aging links oxidative stress and insulin resistance in adipocytes

Telomere shortening is emerging as a biological indicator of accelerated aging and aging-related diseases including type 2 diabetes. While telomere length measurements were largely done in white blood cells, there is lack of studies on telomere length in relation to oxidative stress in target tissues affected in diabetes. Therefore, the aim of this study is to induct oxidative stress in adipocytes and to test whether these adipocytes exhibit shortened telomeres, senescence and functional impairment. 3T3-L1 adipocytes were subjected to oxidative stress and senescence induction by a variety of means for 2 weeks (exogenous application of H2O2, glucose oxidase, asymmetric dimethylarginine (ADMA) and glucose oscillations). Cells were probed for reactive oxygen species generation (ROS), DNA damage, mRNA and protein expression of senescent and pro-inflammatory markers, telomere length and glucose uptake. Compared to untreated cells, both ROS generation and DNA damage were significantly higher in cells subjected to oxidative stress and senescence. Adipocytes subjected to oxidative stress also showed shortened telomeres and increased mRNA and protein expression of p53, p21, TNF alpha and IL-6. Senescent cells were also characterized by decreased levels of adiponectin and impaired glucose uptake. Briefly, adipocytes under oxidative stress exhibited increased ROS generation, DNA damage, shortened telomeres and switched to senescent/pro-inflammatory phenotype with impaired glucose uptake.

Association between large detectable clonal mosaicism and type 2 diabetes with vascular complications

Large chromosomal clonal mosaic events (CMEs) have been suggested to be linked to aging and to predict cancer. Type 2 diabetes (T2D) has been conceptualized as an accelerated-aging disease and is associated with higher prevalence of cancers. Here we aimed to assess the association between T2D and CME occurrence in blood. We evaluated the presence of CMEs in 7,659 individuals (including 2,208 with T2D) using DNA arrays. A significant association between CME occurrence and T2D was found (odds ratio (OR) = 5.3; P = 5.1 × 10(-5)) and was stronger when we only considered non-obese individuals with T2D (OR = 5.6; P = 4.9 × 10(-5)). Notably, CME carriers with T2D had higher prevalence of vascular complications than non-carriers with T2D (71.4% versus 37.1%, respectively; P = 7.7 × 10(-4)). In CME carriers, we found an increase in the percentage of abnormal cells over 6 years (P = 8.60 × 10(-3)). In conclusion, given the increased risk of cancer in CME carriers, our results may have profound clinical implications in patients with severe T2D.

The vascular smooth muscle cell: a therapeutic target in Type 2 diabetes?

The rising epidemic of T2DM (Type 2 diabetes mellitus) worldwide is of significant concern. The inherently silent nature of the disease in its early stages precludes early detection; hence cardiovascular disease is often established by the time diabetes is diagnosed. This increased cardiovascular risk leads to significant morbidity and mortality in these individuals. Progressive development of complications as a result of previous exposure to metabolic disturbances appears to leave a long-lasting impression on cells of the vasculature that is not easily reversed and is termed 'metabolic memory'. SMCs (smooth muscle cells) of blood vessel walls, through their inherent ability to switch between a contractile quiescent phenotype and an active secretory state, maintain vascular homoeostasis in health and development. This plasticity also confers SMCs with the essential capacity to adapt and remodel in pathological states. Emerging clinical and experimental studies propose that SMCs in diabetes may be functionally impaired and thus contribute to the increased incidence of macrovascular complications. Although this idea has general support, the underlying molecular mechanisms are currently unknown and hence are the subject of intense research. The aim of the present review is to explore and evaluate the current literature relating to the problem of vascular disease in T2DM and to discuss the critical role of SMCs in vascular remodelling. Possibilities for therapeutic strategies specifically at the level of T2DM SMCs, including recent novel advances in the areas of microRNAs and epigenetics, will be evaluated. Since restoring glucose control in diabetic patients has limited effect in ameliorating their cardiovascular risk, discovering alternative strategies that restrict or reverse disease progression is vital. Current research in this area will be discussed.

Estimation of expected life-years saved from successful prevention of end-stage renal disease in elderly patients with diabetes: a nationwide study from Taiwan

OBJECTIVE

Because of the increasing incidence and prevalence of diabetes as a leading cause of end-stage renal disease (ESRD) in the aging population, we estimated the expected life-years (LYs) saved from successful prevention of ESRD in elderly patients with diabetes.

RESEARCH DESIGN AND METHODS

We conducted a population-based cohort study using the National Health Insurance Research Database. We identified all incidences of ESRD in the individuals >65 years of age who were receiving maintenance hemodialysis (N = 24,243) from the registry files of catastrophic illnesses in Taiwan from 1 July 1997 to 31 December 2005. We then retrospectively searched the database to determine whether there had been a diagnosis of diabetes in these cases. After the exclusion of individuals with malignancy (n = 3,423), we extrapolated the survival rates through the end of 2006 using the Monte Carlo method. Using the data of preventable ESRD cases due to diabetes and expected years of life lost (EYLL) in each age stratum, we further estimated the expected LYs saved from successful prevention of ESRD in elderly patients with diabetes.

RESULTS

The estimated average EYLL was 10.6-5.8 and 12.3-7.3 years for diabetic males and females, respectively, aged 65-79 years. In total, 5,430.1 LYs and 10,177 LYs could be saved by the successful prevention of ESRD in male and female elderly patients with diabetes, respectively, in a single year.

CONCLUSIONS

The LYs saved by successful prevention of ESRD in elderly patients with diabetes in a single year are substantial and deserve special attention, especially in elderly females.

Impact of Geriatric Conditions Versus Medical Diagnoses on ADL Disability Among Nonagenarians and Centenarians

Objective: The authors investigated the relationship of activities of daily living (ADL) disability with medical diseases and geriatric conditions among nonagenarians and centenarians. Method: Cross-sectional, n = 870 Chinese (age range: 90-108 years). Self-reported medical diseases and geriatric-specific conditions were obtained by face-to-face interviews. Biomedical measurements included systolic/diastolic blood pressure, BMI (body mass index), albumin, fasting glucose, creatinine clearance, hemoglobin, and lipid panel. Results: In bivariate analyses, 4 of 7 geriatric conditions (hearing problems, falls, cognitive impairment, fracture), and 6 of 11 biomedical measurements (fasting glucose, cholesterol, LDL, creatinine clearance, hemoglobin, albumin), but none of 10 medical diseases and no degree of comorbidities, were associated with ADL disability. In four different multivariate logistic regression models, two geriatric conditions (impaired cognition, fracture) were significant in three models, respiratory disease in one model, and fasting glucose in two models. Discussion: This study emphasizes the importance of geriatric conditions and their association with ADL disability among the oldest-old adult population.

Aging, diabetes, and the public health system in the United States

Diabetes (diagnosed or undiagnosed) affects 10.9 million US adults aged 65 years and older. Almost 8 in 10 have some form of dysglycemia, according to tests for fasting glucose or hemoglobin A1c. Among this age group, diagnosed diabetes is projected to reach 26.7 million by 2050, or 55% of all diabetes cases. In 2007, older adults accounted for $64.8 billion (56%) of direct diabetes medical costs, $41.1 billion for institutional care alone. Complications, comorbid conditions, and geriatric syndromes affect diabetes care, and medical guidelines for treating older adults with diabetes are limited. Broad public health programs help, but effective, targeted interventions and expanded surveillance and research and better policies are needed to address the rapidly growing diabetes burden among older adults.

Diabetes and frailty: an emerging issue. Part 1: Sarcopaenia and factors affecting lower limb function

Frailty and sarcopaenia are commonly used terms in the medical management of older people but their relationship to those with diabetes has not been explored in great detail. In this review, we hypothesise that diabetes and frailty are related conditions, and we attempt to explain the nature of this relationship, and consider the possibility that sarcopaenia is an intermediate step.

The critical role of metabolic pathways in aging

Aging is characterized by a deterioration in the maintenance of homeostatic processes over time, leading to functional decline and increased risk for disease and death. The aging process is characterized metabolically by insulin resistance, changes in body composition, and physiological declines in growth hormone (GH), insulin-like growth factor-1 (IGF-1), and sex steroids. Some interventions designed to address features of aging, such as caloric restriction or visceral fat depletion, have succeeded in improving insulin action and life span in rodents. Meanwhile, pharmacologic interventions and hormonal perturbations have increased the life span of several mammalian species without necessarily addressing features of age-related metabolic decline. These interventions include inhibition of the mammalian target of rapamycin and lifetime deficiency in GH/IGF-1 signaling. However, strategies to treat aging in humans, such as hormone replacement, have mostly failed to achieve their desired response. We will briefly discuss recent advances in our understanding of the complex role of metabolic pathways in the aging process and highlight important paradoxes that have emerged from these discoveries. Although life span has been the major outcome of interest in the laboratory, a special focus is made in this study on healthspan, as improved quality of life is the goal when translated to humans.

Accelerated aging as evidenced by increased telomere shortening and mitochondrial DNA depletion in patients with type 2 diabetes

Although shortened telomeres were shown associated with several risk factors of diabetes, there is lack of data on their relationship with mitochondrial dysfunction. Therefore, we compared the relationship between telomere length and mitochondrial DNA (mtDNA) content in patients with type 2 diabetes mellitus (T2DM; n = 145) and in subjects with normal glucose tolerance (NGT; n = 145). Subjects were randomly recruited from the Chennai Urban Rural Epidemiology Study. mtDNA content and telomere length were assessed by Real-Time PCR. Malonodialdehyde, a marker of lipid peroxidation was measured by thiobarbituric acid reactive substances (TBARS) using fluorescence methodology. Adiponectin levels were measured by radioimmunoassay. Oxidative stress as determined by lipid peroxidation (TBARS) was significantly (p < 0.001) higher in patients with T2DM compared to NGT subjects. In contrast, the mean telomere length, adiponectin and mtDNA content were significantly (p < 0.001) lower in patients with T2DM compared to NGT subjects. Telomere length was positively correlated with adiponectin, HDL, mtDNA content and good glycemic/lipid control and negatively correlated with adiposity and insulin resistance. On regression analysis, shortened telomeres showed significant association with T2DM even after adjusting for waist circumference, insulin resistance, triglyceride, HDL, adiponectin, mtDNA & TBARS. mtDNA depletion showed significant association with T2DM after adjusting for waist circumference and adiponectin but lost its significance when further adjusted for telomere length, TBARS and insulin resistance. Our study emphasizes the clustering of accelerated aging features viz., shortened telomeres, decreased mtDNA content, hypoadiponectinemia, low HDL, and increased oxidative stress in Asian Indian type 2 diabetes patients.

Medical care in the nursing home

With the advent of the graying of the baby boomers, there is an urgent need to enhance care in the nursing home. This article focuses on the areas where high-quality care can improve outcomes.

Special considerations for the use of insulin in older adults

OBJECTIVE

The goal of this article is to provide guidance in prescribing insulin for older adults.

BACKGROUND

The prevalence of diabetes increases with age, with almost 30% of the elderly population diagnosed with this metabolic disorder. Along with the well-documented microvascular and microvascular complications of diabetes, older adults are at increased risk of numerous other complications, such as dementia, risk of falling, frailty, and incontinence.

DATA SYNTHESIS

Whether designing a new insulin regimen or adjusting an existing regimen, many factors must be considered; these include advantages and disadvantages of each insulin option; adverse events, particularly hypoglycemia and increased risk of falls; and comorbid conditions. When assessing insulin options for older adults, a thorough evaluation of key features, such as the pharmacokinetics and timing of administration in relation to meals, along with cost, will assist clinicians in selecting an appropriate regimen. Hypoglycemia and risk of falls are increased in older adults; tight glycemic goals must be weighed against the risk of these adverse events. The presence of comorbid conditions may interfere with older adults' ability to inject insulin and monitor their blood sugar appropriately. Specialized devices, such as insulin pens, may offer a means to assist older adults with their insulin therapy.

CONCLUSION

Prescribing insulin to older patients must be individualized and tailored to meet the needs of each individual.

Intermittent parathyroid hormone fails to stimulate osseointegration in diabetic rats

OBJECTIVES

Diabetes is considered a risk factor in the osseointegration of dental implants, which suggests that these patients might benefit from anabolic therapies. Preclinical studies, including investigations by this research group, revealed that intermittent administration of parathyroid hormone (PTH) stimulates bone formation on the surface of titanium implants under physiological conditions. However, the anabolic effect of PTH on osseointegration under the hyperglycemic condition of diabetes is unknown.

METHODS

The ability of PTH to stimulate osseointegration was investigated in 40 female Wistar rats that were randomly divided into the following treatment groups: diabetes, diabetes plus PTH, control, and control plus PTH. Diabetes was induced by intraperitoneal injection of streptozotocin (45 mg/kg) at 1 week before implantation. Rats received PTH at a dose of 60 μg/kg or a vehicle by subcutaneous injection starting at the day of implant insertion into the tibia. Histomorphometric analysis was performed after 4 weeks.

RESULTS

The medullary peri-implant bone area significantly increased in rats receiving PTH in comparison with the control group (41±12% to 20±12%; P<0.01). Moreover, there was an increased bone-to-implant contact (BIC) area in animals treated with PTH (47±18% to 27±16%; P<0.05). In contrast, diabetic rats failed to benefit from the anabolic treatment. A similar peri-implant bone area occurred in the diabetes group, independent of treatment with PTH (13±9% to 15±6%; P>0.05). Moreover, PTH did not affect the BIC area under hyperglycemic conditions (16±12% to 16±8%; P>0.05). No significant changes were observed in the cortical compartment of all groups.

CONCLUSION

These results demonstrate that the metabolic characteristics of the diabetic rats produced a condition that was unable to respond to PTH treatment. These findings led us to hypothesize that metabolic control of diabetes might be a critical determinant when diabetic patients are undergoing anabolic therapy to enhance osseointegration.

Thiazolidinedione treatment and constitutive-PPARgamma activation induces ectopic adipogenesis and promotes age-related thymic involution

Age-related thymic involution is characterized by reduction in T cell production together with ectopic adipocyte development within the hematopoietic and thymic niches. Peroxisome proliferator-activated receptor gamma (PPARgamma) is required for adipocyte development, glucose homeostasis and is a target for several insulin-sensitizing drugs. Our prior studies showed that age-related elevation of PPARgamma expression in thymic stromal cells is associated with thymic involution. Here, using clinically relevant pharmacological and genetic manipulations in mouse models, we provide evidence that activation of PPARgamma leads to reduction in thymopoiesis. Treatment of aged mice with antihyperglycemic PPARgamma-ligand class of thiazolidinedione drug, rosiglitazone caused robust thymic expression of classical pro-adipogenic transcripts. Rosiglitazone reduced thymic cellularity, lowered the naïve T cell number and T cell receptor excision circles (TRECs) indicative of compromised thymopoiesis. To directly investigate whether PPARgamma activation induces thymic involution, we created transgenic mice with constitutive-active PPARgamma (CA-PPARg) fusion protein in cells of adipogenic lineage. Importantly, CA-PPARgamma transgene was expressed in thymus and in fibroblast-specific protein-1/S100A4 (FSP1(+)) cells, a marker of secondary mesenchymal cells. The CAPPARgamma fusion protein mimicked the liganded PPARgamma receptor and the transgenic mice displayed increased ectopic thymic adipogenesis and reduced thymopoiesis. Furthermore, the reduction in thymopoiesis in CA-PPARgamma mice was associated with higher bone marrow adiposity and lower hematopoietic stem cell progenitor pool. Consistent with lower thymic output, CAPPARgamma transgenic mice had restricted T cell receptor repertoire diversity. Collectively, our data suggest that activation of PPARgamma accelerates thymic aging and thymus-specific PPARgamma antagonist may forestall age-related decline in T cell diversity.

Absence of insulin signalling in skeletal muscle is associated with reduced muscle mass and function: evidence for decreased protein synthesis and not increased degradation

Loss of skeletal muscle mass and function is observed in many insulin-resistant disease states such as diabetes, cancer cachexia, renal failure and ageing although the mechanisms for this remain unclear. We hypothesised that impaired insulin signalling results in reduced muscle mass and function and that this decrease in muscle mass and function is due to both increased production of atrogenes and aberrant reactive oxygen species (ROS) generation. Maximum tetanic force of the extensor digitorum longus of muscle insulin receptor knockout (MIRKO) and lox/lox control mice was measured in situ. Muscles were removed for the measurement of mass, histological examination and ROS production. Activation of insulin signalling pathways, markers of muscle atrophy and indices of protein synthesis were determined in a separate group of MIRKO and lox/lox mice 15 min following treatment with insulin. Muscles from MIRKO mice had 36% lower maximum tetanic force generation compared with muscles of lox/lox mice. Muscle fibres of MIRKO mice were significantly smaller than those of lox/lox mice with no apparent structural abnormalities. Muscles from MIRKO mice demonstrated absent phosphorylation of AKT in response to exogenous insulin along with a failure to phosphorylate ribosomal S6 compared with lox/lox mice. Atrogin-1 and MuRF1 relative mRNA expression in muscles from MIRKO mice were decreased compared with muscles from lox/lox mice following insulin treatment. There were no differences in markers of reactive oxygen species damage between muscles from MIRKO mice and lox/lox mice. These data support the hypothesis that the absence of insulin signalling contributes to reduced muscle mass and function though decreased protein synthesis rather than proteasomal atrophic pathways.