The genetics of diabetes mellitus

Genes play an important role in the development of diabetes mellitus. Putative susceptibility genes could be the key to the development of diabetes. Type 1 diabetes mellitus is one of the most common chronic diseases of childhood. A combination of genetic and environmental factors is most likely the cause of Type 1 diabetes. The pathogenetic sequence leading to the selective autoimmune destruction of islet beta-cells and development of Type 1 diabetes involves genetic factors, environmental factors, immune regulation and chemical mediators. Unlike Type 1 diabetes mellitus, Type 2 diabetes is often considered a polygenic disorder with multiple genes located on different chromosomes being associated with this condition. This is further complicated by numerous environmental factors which also contribute to the clinical manifestation of the disorder in genetically predisposed persons. Only a minority of cases of type 2 diabetes are caused by single gene defects such as maturity onset diabetes of the young (MODY), syndrome of insulin resistance (insulin receptor defect) and maternally inherited diabetes and deafness (mitochondrial gene defect). Although Type 2 diabetes mellitus appears in almost epidemic proportions our knowledge of the mechanism of this disease is limited. More information about insulin secretion and action and the genetic variability of the various factors involved will contribute to better understanding and classification of this group of diseases. This article discusses the results of various genetic studies on diabetes with special reference to Indian population.

The effects of lipoic acid and alpha-tocopherol supplementation on the lipid profile and insulin sensitivity of patients with type 2 diabetes mellitus: A randomized, double-blind, placebo-controlled trial

Antioxidants probably play an important role in the etiology of type 2 diabetes (DM2). This study evaluated the effects of supplementation with lipoic acid (LA) and alpha-tocopherol on the lipid profile and insulin sensitivity of DM2 patients. A randomized, double-blind, placebo-controlled trial involving 102 DM2 patients divided into four groups to receive daily supplementation for 4 months with: 600 mg LA (n = 26); 800 mg alpha-tocopherol (n = 25); 800 mg alpha-tocopherol + 600 mg LA (n = 25); placebo (n = 26). Plasma alpha-tocopherol, lipid profile, glucose, insulin, and the HOMA index were determined before and after supplementation. Differences within and between groups were compared by ANOVA using Bonferroni correction. Student`s t-test was used to compare means of two independent variables. The vitamin E/total cholesterol ratio improved significantly in patients supplemented with vitamin E + LA and vitamin E alone (p <= 0.001). There were improvements of the lipid fractions in the groups receiving LA and vitamin E alone or in combination, and on the HOMA index in the LA group, but not significant. The results suggest that LA and vitamin E supplementation alone or in combination did not affect the lipid profile or insulin sensitivity of DM2 patients. (C) 2011 Elsevier Ireland Ltd. All rights reserved.

Diabetes mellitus-related morphoquantitative changes in the celiac ganglion neurons of the dog

Diabetes mellitus is the most common endocrine disturbance of domestic carnivores and can cause autonomic neurological disorders, although these are still poorly understood in veterinary medicine. There is little information available on the quantitative adaptation mechanisms of the sympathetic ganglia during diabetes mellitus in domestic mammals. By combining morphometric methods and NADPH-diaphorase staining (as a possible marker for nitric oxide producing neurons), type I diabetes mellitus-related morphoquantitative changes were investigated in the celiac ganglion neurons in dogs. Twelve left celiac ganglia from adult female German shepherd dogs were examined: six ganglia were from non-diabetic and six from diabetic subjects. Consistent hypertrophy of the ganglia was noted in diabetic animals with increase of 55% in length, 53% in width, and 61.5% in thickness. The ordinary microstructure of the ganglia was modified leading to an uneven distribution of the ganglionic units and a more evident distribution of axon fascicles. In contrast to non-diabetic dogs, there was a lack of NADPH-diaphorase perikarial labelling in the celiac ganglion neurons of diabetic animals. The morphometric study showed that both the neuronal and nuclear sizes were significantly larger in diabetic dogs (1.3 and 1.39 times, respectively). The profile density and area fraction of NADPH-diaphorase-reactive celiac ganglion neurons were significantly larger (1.35 and 1.48 times, respectively) in non-diabetic dogs compared to NADPH-diaphorase-non-reactive celiac ganglion neurons in diabetic dogs. Although this study suggests that diabetic neuropathy is associated with neuronal hypertrophy, controversy remains over the possibility of ongoing neuronal loss and the functional interrelationship between them. It is unclear whether neuronal hypertrophy could be a compensation mechanism for a putative neuronal loss during the diabetes mellitus. (C) 2007 Elsevier Ltd. All rights reserved.

Biodritin microencapsulated human islets of langerhans and their potential for type 1 diabetes mellitus therapy

Background. Microencapsulation of pancreatic islets with polymeric compounds constitutes an attractive alternative therapy for type 1 diabetes mellitus. The major limiting factor is the availability of a biocompatible and mechanically stable polymer. We investigated the potential of Biodritin, a novel polymer constituted of alginate and chondroitin sulfate, for islet microencapsulation. Methods. Biodritin microcapsules were obtained using an air jet droplet generator and gelated with barium or calcium chloride. Microencapsulated rat insulinoma RINm5F cells were tested for viability using the [3-(4,5-dimetyl-thiazol-2-yl)-2,5-diphenyl-tetrazoliumbromide] [MTT] colorimetric assay. Microencapsulated rat pancreatic islets were coincubated with macrophages derived from mouse peritoneal liquid to assess the immunomodulatory potential of the microcapsules, using quantitative real time-PCR (qPCR). Biodritin biocompatibility was demonstrated by subcutaneous injection of empty microcapsules into immunocompetent Wistar rats. Insulin secretion by microencapsulated human pancreatic islets was evaluated using an electrochemoluminescent assay. Microencapsulated human islets transplanted into chemically induced diabetic mice were monitored for reversal of hyperglycemia. Results. The metabolic activity of microencapsulated RINm5F cells persisted for at least 15 days. Interleukin-1 beta expression by macrophages was observed during coculture with islets microencapsulated with Biodritin-CaCl2, but not with Biodritin-BaCl2. No statistical difference in glucose-stimulated insulin secretion was observed between nonencapsulated and microencapsulated islets. Upon microencapsulated islet transplantation, the blood glucose level of diabetic mice normalized; they remained euglycemic for at least 60 days, displaying normal oral glucose tolerance tests. Conclusion. This study demonstrated that Biodritin can be used for islet microencapsulation and reversal of diabetes; however, further investigations are required to assess its potential for long-term transplantation.

Barns upplevelser av att leva med diabetes mellitus typ 1 : samt sjuksköterskans betydelse i deras omvårdnad

Syftet med denna studie har varit att beskriva hur barn med diagnosen diabetes mellitus typ 1 upplever sin sjukdom samt vilken betydelse sjuksköterskan kunde ha i omvårdnaden av dessa barn. Studien har utförts som en systematisk litteraturstudie och tillvägagångssättet har varit att systematiskt söka, kritiskt granska och sammanställa resultat inom det valda ämnesområdet från olika studier. Sökningen har skett i databaserna Elin@Dalarna, Cinahl och Blackwell Synergy. Sökorden som har använts var: diabetes mellitus type 1, diabetes mellitus, children, adolescents, experiences, perspective, nurs* och care i olika kombinationer. Sammanställningen från resultatet visade att barn med diagnosen diabetes mellitus typ 1 upplever sin sjukdom olika utifrån sina egna förutsättningar, kön eller ålder. Det framkom även att sjuksköterskan hade en viktig roll när det gällde att fånga upp barnens upplevelser kring den förändrade livssituationen som uppstått och utifrån detta kartlägga barnens resurser att hantera denna situation. Att då kunna bemöta barnen och deras familjer utifrån egna förutsättningar och att motivera dessa till att sköta den livslånga behandlingen, kan vara avgörande för att få en bra kontroll över diabetes och på så sätt en ökad livskvalité och ett gott välbefinnande.

Patienters upplevelser samt sjuksköterskans roll i undervisningen till patienter med Diabetes mellitus typ 2

Syfte: Syftet med denna studie var att undersöka hur patienter upplevde patient-undervisningen samt hur sjuksköterskans roll såg ut i patientundervisningen. Metod: Uppsatsen har genomförts som en systematisk litteraturstudie. Artiklar har sökts i databaserna ELIN samt Cinahl. Artiklar publicerade mellan 1999-2009 och som var tillgängliga i fulltext inkluderades i resultatdelen som omfattade 14 kvalitativa studier samt en litteraturstudie. Resultat: I resultatet framgick att patienterna upplevde att gruppundervisning var ett bra alternativ till enskild undervisning då de kunde ta del av andras erfarenheter och på det sättet få mer kunskap om sjukdomen. Dessutom upplevde de att det var givande att träffa personer med samma sjukdom. I studien framgick att enskild undervisning var önskvärt från både patienter och sjuksköterskor då det kunde upplevas lättare att ta upp de frågor de hade där. Sjuksköterskan kunde vara ett stort stöd för patienten. Förutom att förmedla sina kunskaper och undervisa patienten var lyssna, uppmuntra och stötta något som sjuksköterskorna ansåg vara viktigt i mötet med patienten. Något som togs upp av patienter och sjuksköterskorna var att de ansåg att det vore bra om patienterna under besöken träffade samma personer då det skulle underlätta uppföljningarna.

Icke-följsamhet vid diabetes mellitus : en litteraturstudie

Syftet med föreliggande studie var att beskriva vad personer med diabetes anser inverka på deras möjlighet och vilja att följa egenvårdsråd (patientperspektivet) och att beskriva omvård-nad som stöder följsamhet (sjukvårdsperspektivet). Studien har genomförts som en litteratur-studie. Det visade sig att alla krav för att hålla sjukdomen under kontroll innebär livsstilsför-ändringar, som kan vara så utmanande för patienten, att han kanske inte kan eller vill vidta dessa. Bristande kunskap om sjukdomen och om dess egenvårdskrav kan göra honom dåligt emotionellt anpassad till denna, det vill säga han har inte accepterat att han har sjukdomen och han vill inte låta dess egenvårdskrav inkräkta på det sociala livet. Detta ger honom för-sämrade möjligheter att hantera sjukdomen på ett bra sätt. Barriärer av olika slag kan uppstå mellan patient och vårdgivare. Det kan röra sig om en upplevd brist på information och stöd när diabetes diagnosticerats eller en känsla av att vara utsatt för läkarens eller sjuksköterskans stereotypa föreställningar och/eller att bli paternalistiskt behandlad. Till barriärer räknas även klinisk misskötsel, det vill säga att läkare/sjuksköterska inte följer vedertagna riktlinjer för be-handling.Vad som kan inverka positivt på följsamheten är patientens stöd av anhöriga eller andra i det sociala nätverket. Omvårdnad som stöder följsamhet visade sig varapatientundervisning, främst om den inriktades på att öka patientens självständighet genom att låta undervisningen pågå under en längre tid, så att patienten hinner integrera sin nya kunskap med det dagliga livet. Med eller utan patientundervisning tar det tid att bygga upp ett socialt stöd och ett förtroende mellan patient och vårdare.

Patienters upplevelser av livskvalitet vid nydiagnostiserad typ 2 Diabetes Mellitus : En intervjustudie

Syfte: Att undersöka patienters upplevelser av livskvalitet vid nydiagnostiserad typ 2 Diabetes Mellitus. Metod: En empirisk studie med en kvalitativ ansats som innefattade tio deltagare med nydiagnostiserad typ 2 Diabetes Mellitus. Semistrukturerade intervjuer genomfördes utifrån en intervjuguide där insamlad data analyserades med kvalitativ manifest innehållsanalys. Resultat: Studien resulterade i fyra huvudkategorier och tio subkategorier. Upplevelsen av att få ett diagnosbesked varierade mellan deltagarna, för vissa deltagarna var beskedet inte förvånande medan andra upplevde känslor av chock och förnekelse. Deltagarna upplevde positiva förändringar, exempelvis viktnedgång och förbättrad hälsa men även negativa förändringar, exempelvis att vara beroende av läkemedel. Vissa upplevde ingen förändring alls. Typ 2 Diabetes Mellitus påverkade inte deltagarnas fysiska eller psykiska hälsa i de flesta fall. Deltagarna ansåg det som viktig att få stöd från både omgivningen och hälso- och sjukvården. Konklusion: Känslorna över ett diagnosbesked kunde variera men upplevelsen av livskvalitet påverkades inte av Typ 2 Diabetes Mellitus i de flesta fall i studien. Patientens inställning till att leva med Typ 2 Diabetes Mellitus inverkade på förmågan till att utföra egenvård, och distriktsköterskans stöd och engagemang ansågs vara betydelsefullt i sjukdomsprocessen.

Improved skeletal muscle oxidative enzyme activity and restoration of PGC-1α and PPARß/δ gene expression upon rosiglitazone treatment in obese patients with type 2 diabetes mellitus

Objective: To examine whether rosiglitazone alters gene expression of some key genes involved in mitochondrial biogenesis and oxidative capacity in skeletal muscle of type 2 diabetic patients, and whether this is associated with alterations in skeletal muscle oxidative capacity and lipid content.

Design: Skeletal muscle gene expression, mitochondrial protein content, oxidative capacity and lipid accumulation were measured in muscle biopsies obtained from diabetic patients, before and after 8 weeks of rosiglitazone treatment, and matched controls. Furthermore, whole-body insulin sensitivity and substrate utilization were assessed.

Subjects: Ten obese type 2 diabetic patients and 10 obese normoglycemic controls matched for age and BMI.

Methods: Gene expression and mitochondrial protein content of complexes I–V of the respiratory chain were measured by quantitative polymerase chain reaction and Western blotting, respectively. Histochemical staining was used to quantify lipid accumulation and complex II succinate dehydrogenase (SDH) activity. Insulin sensitivity and substrate utilization were measured during a hyperinsulinemic–euglycemic clamp with indirect calorimetry.

Results: Skeletal-muscle mRNA of PGC-1a and PPARb/d – but not of other genes involved in glucose, fat and oxidative metabolism – was significantly lower in diabetic patients (Po0.01). Rosiglitazone significantly increased PGC-1a (B2.2-fold, Po0.01) and PPARb/d (B2.6-fold, Po0.01), in parallel with an increase in insulin sensitivity, SDH activity and metabolic flexibility (Po0.01). Surprisingly, none of the measured mitochondrial proteins was reduced in type 2 diabetic patients, nor affected by rosiglitazone treatment. No alterations were seen in muscular fat accumulation upon treatment.

Conclusion: These results suggest that the insulin-sensitizing effect of rosiglitazone may involve an effect on muscular oxidative capacity, via PGC-1a and PPARb/d, independent of mitochondrial protein content and/or changes in intramyocellular lipid.

Aerobic exercise and resistance training for the management of type 2 diabetes mellitus

BACKGROUND
Implementation of a structured physical exercise program can improve glycemic control in patients with type 2 diabetes mellitus.

OBJECTIVE
To evaluate the efficacy of aerobic exercise and resistance training (either alone or in combination) in the management of type 2 diabetes mellitus.

DESIGN AND INTERVENTION
DARE (Diabetes Aerobic and Resistance Exercise) was a 26-week, single-center, parallel-group, randomized, controlled trial of patients with type 2 diabetes mellitus of >6 months' duration. Participants were aged 39-70 years with a baseline [HbA.sub.1c] level 6.6-9.9%. Exclusion criteria included current insulin therapy, regular exercise regime and blood pressure >160/95 mmHg. All participants underwent a 4-week run-in period that comprised 12 sessions of combined aerobic exercise and resistance training; participants who attended [greater than or equal to] 10 sessions were eligible to enter the study. Eligible participants were randomly allocated to one of four groups: aerobic exercise alone; resistance training alone; combined aerobic exercise and resistance training; and no intervention (control group). Exercise was performed three times weekly. The aerobic exercise group progressed from 15-20 min on a treadmill or bicycle ergometer per session at 60% of the maximum heart rate to 45 min per session at 75% of the maximum heart rate. The resistance training group performed 7 different exercises on weight machines per 45 min session, and progressed to 2-3 sets of each exercise at the maximum weight that could be lifted 7-9 times. The combined exercise group performed the full aerobic exercise program plus the full resistance training program. Participants in the control group reverted to their pre-study exercise levels.

OUTCOME MEASURES
The primary outcome measure was the change in [HbA.sub.1c] from baseline. Secondary outcome measures included changes in blood pressure, lipid profile, and body composition.

RESULTS
A total of 251 participants were eligible for intervention. The median session attendance was 80% (aerobic exercise), 85% (resistance training) and 86% (combined exercise). When compared with the control group, the HbA1c levels were reduced by 0.50% in the aerobic exercise group (P = 0.007) and by 0.38% in the resistance training group (P = 0.038). The combined exercise group had an additional reduction of 0.46% when compared with the aerobic exercise group (P = 0.014) and of 0.59% when compared with the resistance training group (P = 0.001). Decreases in [HbA.sub.1c] levels were greatest for participants with a baseline [HbA.sub.1c] level = 7.5% (P <0.001). For participants with a baseline level [HbA.sub.1c] <7.5%, significant improvements in glycemic control were observed in the combined exercise group only (P = 0.002). Changes in blood pressure and lipid profiles did not differ between the groups. By contrast, participation in a structured exercise program improved body composition.

CONCLUSION
Although aerobic exercise or resistance training alone improved glycemic control, additional improvements were observed with the combined exercise regimen.

Risk of cardiovascular and all-cause mortality in individuals with diabetes mellitus, impaired fasting glucose, and impaired glucose tolerance. The Australian Diabetes, Obesity and Lifestyle Study (AusDiab)

Background--Diabetes mellitus increases the risk of cardiovascular disease (CVD) and all-cause mortality. The relationship between milder elevations of blood glucose and mortality is less clear. This study investigated whether impaired fasting glucose and impaired glucose tolerance, as well as diabetes mellitus, increase the risk of all-cause and CVD mortality.

Methods and Results--In 1999 to 2000, glucose tolerance status was determined in 10 428 participants of the Australian Diabetes, Obesity, and Lifestyle Study (AusDiab). After a median follow-up of 5.2 years, 298 deaths occurred (88 CVD deaths). Compared with those with normal glucose tolerance, the adjusted all-cause mortality hazard ratios (HRs) and 95% confidence intervals (CIs) for known diabetes mellitus and newly diagnosed diabetes mellitus were 2.3 (1.6 to 3.2) and 1.3 (0.9 to 2.0), respectively. The risk of death was also increased in those with impaired fasting glucose (HR 1.6, 95% CI 1.0 to 2.4) and impaired glucose tolerance (HR 1.5, 95% CI 1.1 to 2.0). Sixty-five percent of all those who died of CVD had known diabetes mellitus, newly diagnosed diabetes mellitus, impaired fasting glucose, or impaired glucose tolerance at baseline. Known diabetes mellitus (HR 2.6, 95% CI 1.4 to 4.7) and impaired fasting glucose (HR 2.5, 95% CI 1.2 to 5.1) were independent predictors for CVD mortality after adjustment for age, sex, and other traditional CVD risk factors, but impaired glucose tolerance was not (HR 1.2, 95% CI 0.7 to 2.2).

Conclusions--This study emphasizes the strong association between abnormal glucose metabolism and mortality, and it suggests that this condition contributes to a large number of CVD deaths in the general population. CVD prevention may be warranted in people with all categories of abnormal glucose metabolism.

The metabolic syndrome as a predictor of incident diabetes mellitus in Mauritius

Aims : To assess the utility of the metabolic syndrome (MetS) and a Diabetes Predicting Model as predictors of incident diabetes.

Methods : A longitudinal survey was conducted in Mauritius in 1987 (n = 4972; response 80%) and 1992 (n = 3685; follow-up 74.2%). Diabetes status was retrospectively determined using 1999 World Health Organization (WHO) criteria. MetS was determined according to four definitions and sensitivity, positive predictive value (PPV), specificity and the association with incident diabetes before and after adjustment for MetS components calculated.

Results : Of the 3198 at risk, 297 (9.2%) developed diabetes between 1987 and 1992. The WHO MetS definition had the highest prevalence (20.3%), sensitivity (42.1%) and PPV (26.8%) for prediction of incident diabetes, the strongest association with incident diabetes after adjustment for age and sex [odds ratio 4.6 (3.5–6.0)] and was the only definition to show a significant association after adjustment for its component parts (in men only). The low prevalence and sensitivity of the International Diabetes Federation (IDF) and ATPIII MetS definitions resulted from waist circumference cut-points that were high for this population, particularly in men, and both were not superior to a diabetes predicting model on receiver operating characteristic analysis.

Conclusions : Of the MetS definitions tested, the WHO definition best identifies those who go on to develop diabetes, but is not often used in clinical practice. If cut-points or measures of obesity appropriate for this population were used, the IDF and ATPIII MetS definitions could be recommended as useful tools for prediction of diabetes, given their relative simplicity.