Changing prevalence of juvenile-onset diabetes mellitus

Adherence to Mediterranean Diet and Risk of Cancer: An Updated Systematic Review and Meta-Analysis

The aim of the present systematic review and meta-analysis was to gain further insight into the effects of adherence to Mediterranean Diet (MedD) on risk of overall cancer mortality, risk of different types of cancer, and cancer mortality and recurrence risk in cancer survivors. Literature search was performed using the electronic databases PubMed, and Scopus until 25 August 2017. We included randomized trials (RCTs), cohort (for specific tumors only incidence cases were used) studies, and case-control studies. Study-specific risk ratios, hazard ratios, and odds ratios (RR/HR/OR) were pooled using a random effects model. Observational studies (cohort and case-control studies), and intervention trials were meta-analyzed separately. The updated review process showed 27 studies that were not included in the previous meta-analysis (total number of studies evaluated: 83 studies). An overall population of 2,130,753 subjects was included in the present update. The highest adherence score to a MedD was inversely associated with a lower risk of cancer mortality (RRcohort: 0.86, 95% CI 0.81 to 0.91, I² = 82%; n = 14 studies), colorectal cancer (RRobservational: 0.82, 95% CI 0.75 to 0.88, I² = 73%; n = 11 studies), breast cancer (RRRCT: 0.43, 95% CI 0.21 to 0.88, n = 1 study) (RRobservational: 0.92, 95% CI 0.87 to 0.96, I² = 22%, n = 16 studies), gastric cancer (RRobservational: 0.72, 95% CI 0.60 to 0.86, I² = 55%; n = 4 studies), liver cancer (RRobservational: 0.58, 95% CI 0.46 to 0.73, I² = 0%; n = 2 studies), head and neck cancer (RRobservational: 0.49, 95% CI 0.37 to 0.66, I² = 87%; n = 7 studies), and prostate cancer (RRobservational: 0.96, 95% CI 0.92 to 1.00, I² = 0%; n = 6 studies). Among cancer survivors, the association between the adherence to the highest MedD category and risk of cancer mortality, and cancer recurrence was not statistically significant. Pooled analyses of individual components of the MedD revealed that the protective effects appear to be most attributable to fruits, vegetables, and whole grains. The updated meta-analysis confirms an important inverse association between adherence to a MedD and cancer mortality and risk of several cancer types, especially colorectal cancer. These observed beneficial effects are mainly driven by higher intakes of fruits, vegetables, and whole grains. Moreover, we were able to report for the first time a small decrease in breast cancer risk (6%) by pooling seven cohort studies.

The Influence of the Microbiome on Type 1 Diabetes

Type 1 diabetes (T1D) is characterized by the autoimmune destruction of pancreatic β cells. The rapid rise in T1D incidence during the past 50 y suggests environmental factors contribute to the disease. The trillion symbiotic microorganisms inhabiting the mammalian gastrointestinal tract (i.e., the microbiota) influence numerous aspects of host physiology. In this study we review the evidence linking perturbations of the gut microbiome to pancreatic autoimmunity. We discuss data from rodent models demonstrating the essential role of the gut microbiota on the development and function of the host's mucosal and systemic immune systems. Furthermore, we review findings from human longitudinal cohort studies examining the influence of environmental and lifestyle factors on microbiota composition and pancreatic autoimmunity. Taken together, these data underscore the requirement for mechanistic studies to identify bacterial components and metabolites interacting with the innate and adaptive immune system, which would set the basis for preventative or therapeutic strategies in T1D.

Nutrition, aging and cancer: lessons from dietary intervention studies

There is convincing epidemiological and clinical evidence that, independent of aging, lifestyle and, notably, nutrition are associated with development or progression of major human cancers, including breast, prostate, colorectal tumors, and an increasingly large collection of diet-related cancers. Mechanisms underlying this association are mostly related to the distinct epigenetic effects of different dietary patterns. In this context, Mediterranean diet has been reported to significantly reduce mortality rates for various chronic illnesses, including cardiovascular diseases, neurodegenerative diseases and cancer. Although many observational studies have supported this evidence, dietary intervention studies using a Mediterranean dietary pattern or its selected food components are still limited and affected by a rather large variability in characteristics of study subjects, type and length of intervention, selected end-points and statistical analysis. Here we review data of two of our intervention studies, the MeDiet study and the DiMeSa project, aimed at assessing the effects of traditional Mediterranean diet and/or its component(s) on a large panel of both plasma and urine biomarkers. Both published and unpublished results are presented and discussed.

Islet transplantation from a nationally funded UK centre reaches socially deprived groups and improves metabolic outcomes

AIMS/HYPOTHESIS

Type 1 diabetes complicated by hypoglycaemia is prevalent in socioeconomically deprived populations. Islet transplantation is of proven efficacy in type 1 diabetes complicated by hypoglycaemia, but it is not known if nationally funded programmes reach the socioeconomically deprived. Our aim was to determine: (1) socioeconomic indices in participants referred to our nationally funded programme; and (2) if metabolic outcomes in our transplant recipients were improved.

METHODS

Participants referred (n = 106) and receiving transplants (n = 18; 32 infusions) were examined with respect to socioeconomic status (deprivation category score) and their ability to work and drive. In participants followed for ≥12 months after transplantation, metabolic and anthropometric measurements (n = 14) were recorded pre- and post-transplant (assessed ~1, ~3, ~6 and ~12 months with mixed-meal tolerance tests and 6 day continuous glucose monitoring assessments). Donor data was also examined.

RESULTS

There was a greater prevalence of socioeconomic deprivation in referred and transplant recipients than the general population (p < 0.05). Of the transplant recipients, 73% were socioeconomically deprived, 88% did not hold a driver's license and 94% had reduced ability to work (all p < 0.01 vs referred participants). Donors were predominantly obese and included circulatory death donors. At 12 months, 93% of participants who had received transplants had graft function, diminished frequency of hypoglycaemia (10 [4-11] vs 0 [0-2] hypoglycaemic episodes/week), improved awareness of hypoglycaemia (Gold score 7 [5-7] vs 1 [1-2]) and glycaemic control (HbA1c: 7.9% [7.2-8.5%]; 63 [55-69] mmol/mol vs 7.2% [6.8-7.5%]; 55 [51-58] mmol/mol), diminished glycaemic lability and decreased central adiposity (all p < 0.05).

CONCLUSIONS/INTERPRETATION

A nationally funded islet transplant programme reaches the socioeconomically deprived and outcomes are significantly improved in this group.

The changing landscape of type 1 diabetes: recent developments and future frontiers

Type 1 diabetes (T1D) research has made great strides over the past decade with advances in understanding the pathogenesis, natural history, candidate environmental exposures, exposure triggering time, disease prediction, and diagnosis. Major monitoring efforts have provided baseline historical measures, leading to better epidemiological studies incorporating longitudinal biosamples (ie, biobanks), which have allowed for new technologies ('omics') to further expose the etiological agents responsible for the initiation, progression, and eventual clinical onset of T1D. These new frontiers have brought forth high-dimensionality data, which have furthered the evidence of the heterogeneous nature of T1D pathogenesis and allowed for a more mechanistic approach in understanding the etiology of T1D. This review will expand on the most recent advances in the quest for T1D determinants, drawing upon novel research tools that epidemiology, genetics, microbiology, and immunology have provided, linking them to the major hypotheses associated with T1D etiology, and discussing the future frontiers.

The great weight gain experiment, accelerators, and their implications for autoantibodies in diabetes

Perspective on the paper by Reinehr et al (see page 473)

The rise of childhood type 1 diabetes in the 20th century

The incidence of childhood type 1 diabetes increased worldwide in the closing decades of the 20th century, but the origins of this increase are poorly documented. A search through the early literature revealed a number of useful but neglected sources, particularly in Scandinavia. While these do not meet the exacting standards of more recent surveys, tentative conclusions can be drawn concerning long-term changes in the demography of the disease. Childhood type 1 diabetes was rare but well recognized before the introduction of insulin. Low incidence and prevalence rates were recorded in several countries over the period 1920-1950, and one carefully performed study showed no change in childhood incidence over the period 1925-1955. An almost simultaneous upturn was documented in several countries around the mid-century. The overall pattern since then is one of linear increase, with evidence of a plateau in some high-incidence populations and of a catch-up phenomenon in some low-incidence areas. Steep rises in the age-group under 5 years have been recorded recently. The disease process underlying type 1 diabetes has changed over time and continues to evolve. Understanding why and how this produced the pandemic of childhood diabetes would be an important step toward reversing it.

Diabetes prevalence and socioeconomic status: a population based study showing increased prevalence of type 2 diabetes mellitus in deprived areas

OBJECTIVE

To establish the relation between socioeconomic status and the age-sex specific prevalence of type 1 and type 2 diabetes mellitus. The hypothesis was that prevalence of type 2 diabetes would be inversely related to socioeconomic status but there would be no association with the prevalence of type 1 diabetes and socioeconomic status.

SETTING

Middlesbrough and East Cleveland, United Kingdom, district population 287,157.

PATIENTS

4313 persons with diabetes identified from primary care and hospital records.

RESULTS

The overall age adjusted prevalence was 15.60 per 1000 population. There was a significant trend between the prevalence of type 2 diabetes and quintile of deprivation score in men and women (chi 2 for linear trend, p < 0.001). In men the prevalence in the least deprived quintile was 13.4 per 1000 (95% confidence intervals (95% CI) 11.44, 15.36) compared with 17.22 per 1000 (95% CI 15.51, 18.92) in the most deprived. For women the prevalence was 10.84 per 1000 (95% CI 9.00, 12.69) compared with 15.48 per 1000 (95% CI 13.84, 17.11) in the most deprived. The increased prevalence of diabetes in the most deprived areas was accounted for by increased prevalence of type 2 diabetes in the age band 40-69 years. There was no association between the prevalence of type 1 diabetes and socioeconomic status.

CONCLUSION

These data confirm an inverse association between socioeconomic status and the prevalence of type 2 diabetes in the middle years of life. This finding suggests that exposure to factors that are implicated in the causation of diabetes is more common in deprived areas.

Increased prevalence of insulin-treated diabetes mellitus in Funen County, Denmark

OBJECTIVE

To determine the prevalence of insulin-treated diabetes mellitus in Funen County, Denmark as of 1 July 1987 and compare the findings with those of a similar study from 1973.

DESIGN

The population was identified by insulin prescriptions collected during a 1 year period. The identity of the prescription holders, the diagnosis and the date of diagnosis were verified from medical records and public registers.

RESULTS

The estimated degree of ascertainment of the material is 0.95-0.97. The prevalence rates (per 1000 of the population) of insulin-treated diabetes mellitus as of 1 July 1987 are: 4.74 (95% Cl 4.66-4.82) for all cases, 2.08 (95% Cl 2.01-2.15) for the group with onset of diabetes before age 30 years and 2.66 (95% Cl 2.59-2.73) for the group with onset after age 30 years. These figures correspond to increases of 39, 26 and 51% (P < 0.001) on data collected in 1973.

CONCLUSIONS

There was a significant increase in the prevalence of insulin-treated diabetes mellitus in Funen County, Denmark from 1973 to 1987. Analysis of the data shows that an important factor for this increase is a liability to start insulin treatment of type 2 (non-insulin-dependent) diabetes mellitus at an earlier stage than previously. Also, the data suggest that improved prognosis for diabetic patients as well as an increasing incidence of diabetes mellitus are factors involved in the increase.

Etiological aspects of insulin-dependent diabetes mellitus: an epidemiological perspective

The mechanism of beta-cell destruction leading to insulin dependent diabetes is probably a cell mediated auto-immune process occurring in genetically susceptible individuals. Since 50-70% of monozygotic twins will not get the disease non-genetic risk factors must play an important role in the etiology of the disease. During the past decade population based epidemiological studies have identified several risk determinants for insulin dependent diabetes. Based on these studies a multifactorial hypothesis of causation is proposed. Some risk determinants (maternal child blood group incompatibility, fetal viral infections, early exposure to cow's milk proteins, a high exposure level of nitrosamines) may independently initiate the autoimmune process by causing the initial damage of the beta-cell, leading to antigen release. Other risk determinants may promote an already ongoing autoimmune destructive process through induction of lymphokine release or by causing an increased work load on the beta-cell. Risk factors that may increase the peripheral need for insulin (infectious diseases, cold environment, a high growth rate and stressful life events) may act as promoters of the beta-cell destruction but also disclose the beta-cell impairment and make the disease clinically overt. Possibilities of different risk profiles in different age groups and of synergism between different risk factors are also discussed.

The incidence of male childhood type 1 (insulin-dependent) diabetes mellitus is rising rapidly in The Netherlands

This study evaluates the cumulative incidence of Type 1 (insulin-dependent) diabetes mellitus in male army conscripts 0-18 (inclusive) years of age in the Netherlands (birth cohorts) over 10 years. Data from 2136 cases were retrieved from files of the conscript registry of the Royal Dutch Army. Ascertainment was sought by the capture-recapture method, achieving an average ascertainment rate of 89.7%. Poisson regression modelling was used to determine the change in incidence over time. A significant non-linear increase in the incidence of insulin-dependency in the birth cohorts of 1960-1970 was found. The cumulative incidences of the early birth cohorts 1.85/1000 (1960), 1.76/1000 (1961), 1.11/1000 (1962) were considerably lower than of the later birth cohorts 1.96/1000 (1968), 2.11/1000 (1969), 2.12/1000 (1970). Overall the risk of Type 1 diabetes increased on the average 4.4% with each annual birth cohort. Only for the 1962 birth cohort was a significant dip in the incidence observed. The results indicate a rapidly increasing incidence of diabetes in males in the Netherlands consistent with the concurrent rapid rise in Northern Europe, found in both sexes.

A review of child health in the 1958 birth cohort: National Child Development Study

In the week 3-9 March 1958, 98% of all births in England, Scotland and Wales (approximately 17,000) were studied in the Perinatal Mortality Survey. The follow-up of surviving children, known as the National Child Development Study, comprises four major sweeps at ages 7, 11, 16 and 23. Medical examinations were conducted at each age, except at 23 when health was self-reported. Details of the child's family background and socio-economic circumstances were recorded, together with assessments of their social development and educational attainment. Seventy-six per cent of the target population were interviewed at age 23. The health of subjects in the 1958 cohort has been described in over 200 publications but there is no comprehensive account of findings from birth to age 23. This overview attempts to redress this. As new data are gathered from the study subjects at age 33, opportunities will exist to investigate associations between childhood factors and health in midlife. Data on their partners and children will be included, allowing studies of inter-generational and family health. Further indications of changing illness patterns will be possible from comparisons with data collected on earlier and later born cohorts.

Incidence of juvenile type 1 (insulin-dependent) diabetes mellitus in France

The incidence rate of juvenile Type 1 (insulin-dependent) diabetes in France was reported as the lowest in Europe 13 years ago, but during the recent years increasing rates have been observed in different European countries. A prospective programme has been designed to study the incidence rate of Type 1 diabetes in patients up to 20 years of age in four regions located in the north and south of France (population less than 20 years = 2.31 million inhabitants; 15% of the French population). All cases were independently identified by four specially trained research assistants through hospital admission files, paediatricians, diabetologists and general practitioners. A specific questionnaire was filled out for each newly diagnosed case. Degree of ascertainment was 96% with the data from Sécurité Sociale, the French National Health Insurance. In 1988, 166 cases of juvenile Type 1 diabetes were identified. The incidence rate was 7.17 cases per 10(5) children (95% confidence interval = 6.1-8.2/10(5). The values were not statistically different among the four regions. Age specific incidence rates were as follows: 0-4 years = 3.8; 5-9 years = 8.0; 10-14 years = 9.7 and 15-19 years = 7.3/10(5). Sex ratio was 1.2 (male/female). These data indicate that incidence of juvenile Type 1 diabetes in France was higher in 1988 than previously reported but remains lower than in Northern Europe. This is consistent with the concept of a north to south gradient of the disease.

The challenge of childhood diabetes mellitus in India

The prevalence of DM is about 0.4/1000 children with a lower incidence in the rural areas. Children comprise 3-5% of the total diabetics. A study of 55 pediatric cases of DM (1980-84) showed that only 22 (40%) had ketoacidosis on admission. Ten (18.2%) had onset of illness before 4 years of age. HLA antigen studies in childhood IDDM have shown a positive linkage disequilibrium with Bw21 (RR-12.7), and DR3 (RR = 16.6). Prevalence of islet cell antibodies (ICA) was 30.9% (n = 110) as compared with 0.8% in controls. Antibodies against Coxsackie B2 virus were increased (75.5% vs 46.4% in controls). The C-peptide content was substantially low. Malnutrition related DM occurs in adolescents in some parts of India. It is characterized by moderate hyperglycemia, low serum glycerol, relative insulin insensitivity, and pancreatic malformation/calcification in about 1/4 of subjects. There is no association with HLA antigens or ICA, and the precise etiology is unclear. Mortality was 3.6% in patients admitted in our hospital but is higher in other regions due to poverty and relative lack of health care facilities.

The epidemiology of diabetes in childhood with special reference to the Orient: implications for mechanism of beta cell damage

Epidemiologic studies are providing important new insights into the etiology and clinical course of IDDM as well as providing critically needed data on the magnitude of the problem in different parts of the world. The development of national IDDM registries have documented extraordinary differences in diabetes incidence and prevalence, with the highest incidence figures in Finland (greater than 30/100,000/yr) and the lowest in the Orient with Korea reporting incidence rates below 1 and Japan between 1.0-2.4/100,000/yr. The great geographic variation in expression of diabetes in childhood is strongly supportive of environmental factors playing a major role in the etiology of disease. Our studies document a linear correlation between IDDM incidence and distance from the equator and a similar but inverse correlation with mean annual environmental temperature. Other workers find a direct correlation with dairy product consumption. Factors that may play a role in beta cell damage include viral infections, environmental toxins, nutrients and stress factors. Because of the low incidence of IDDM among children living in Asia it is most important to expand the current national registries in the Asian countries and begin a careful study of the environmental differences within Asian countries as well as comparison of studies between countries with very high incidence rates and those with the lowest rates.

Incidence of insulin dependent diabetes in England: a study in the Oxford region, 1985-6

OBJECTIVE

To determine the incidence of insulin dependent diabetes mellitus up to the age of 21 in a geographically defined population in England with independent validation of completeness of case ascertainment.

DESIGN

Prospective registration of newly diagnosed cases supplemented by centralised hospital discharge records and death certificates. Validation of ascertainment from general practitioners.

SETTING

Oxford Regional Health Authority area (population 2.4 million).

PATIENTS

All patients with insulin dependent diabetes diagnosed below age 21 during 1985-6 and resident in the region at the time of diagnosis.

INTERVENTIONS

None.

END POINT

Validation of a method of case ascertainment for assessing temporal variation in incidence of insulin dependent diabetes.

MEASUREMENTS AND MAIN RESULTS

The overall yearly incidence of newly diagnosed insulin dependent diabetes mellitus in people under 21 was 15.6 cases/100,000 (95% confidence interval 13.6 to 17.6). Among males the incidence was 16.8 cases (14.0 to 19.7)/100,000 and among females 14.3 cases (11.6 to 17.1)/100,000. The highest incidence, in the 10-14 year age group, was 26.4 (20.9 to 31.8) new cases/100,000 population yearly. Case ascertainment was greater than 95%.

CONCLUSIONS

The incidence of insulin dependent diabetes in England is considerably higher than reported from large scale studies. It is consistent with described patterns of geographical variation. The figures provide a baseline for assessing temporal change.

The incidence of type 1 (insulin-dependent) diabetes mellitus in subjects aged 0-19 years in Luxembourg: a retrospective study from 1977 to 1986

A decrease in the incidence of Type 1 (insulin-dependent) diabetes mellitus in the age group 0-14 years has been observed from north to south over north-western Europe. To evaluate whether this trend could be found in Luxembourg (a small country between the Netherlands and France) we performed a retrospective study over a period of 10 years. Information concerning all Type 1 diabetic patients (aged 0-19 years at diagnosis), diagnosed between January 1, 1977 and December 31, 1986 was obtained through paediatricians, internists, general practitioners and the Luxembourg Diabetes Association (LDA). The LDA was used as the ascertainment group (to estimate the real number and incidence of Type 1 diabetes mellitus). During the study period 91 Type 1 diabetic patients aged between 0-19 years were diagnosed. An incidence of 11.2 was found in boys (0-19 years). Girls in the same age group showed a considerably lower incidence of 8.8. Standardised incidence (using as standard the world population) revealed an almost similar incidence in the Netherlands and Luxembourg (respectively 10.3 and 10.2) for the age group aged 0-14 years. In France a considerably lower incidence is found (3.6). To what extent different methodology contributes to the differences remains to be clarified. Further prospective studies are necessary to investigate the role of environmental and genetic factors.