The epidemic of NIDDM in Asian and Pacific Island populations: prevalence and risk factors

Evaluation of neonatal streptozotocin induced diabetic rat model for the development of cataract

Type 2 diabetes (T2D) generally follows prediabetes (PD) conditions such as impaired fasting glucose (IFG) and/or impaired glucose tolerance (IGT). Although studies reported an association of IGT or IFG with cataract, the experimental basis for PD associated cataract is not known. Hence, we evaluated neonatal streptozotocin (nSTZ) induced rat model to study PD associated cataractogenesis by injecting STZ to two-day old rats. While majority (70%) of nSTZ injected pups developed IGT (nSTZ-PD) by two months but not cataract even after seven months, remaining (30%) nSTZ rats developed hyperglycemia (nSTZ-D) by two months and mature cataract by seven months. Lens biochemical analysis indicated increased oxidative stress as indicated by increased SOD activity, lipid peroxidation, and protein carbonyl levels in nSTZ-D cataractous lens. There was also increased polyol pathway as assessed by aldose reductase activity and sorbitol levels. Though nSTZ-PD animals have not shown any signs of lenticular opacity, insolubilization of proteins along with enhanced polyol pathway was observed in the lens. Further there was increased oxidative stress in lens of IGT animals. These results suggest that oxidative stress along with increased polyol pathway might play a role in IGT-associated lens abnormalities. In conclusion, nSTZ-PD rat model could aid to investigate IGT-associated lens abnormalities.

Comparative clinical pharmacokinetics of dipeptidyl peptidase-4 inhibitors

Dipeptidyl peptidase-4 (DPP-4) inhibitors collectively comprise a presently unique form of disease management for persons with type 2 diabetes mellitus. The aim of this review is to compare the clinical pharmacokinetics of available DPP-4 inhibitors (alogliptin, linagliptin, saxagliptin, sitagliptin and vildagliptin) for the purpose of identifying potential selection preferences according to individual patient variables and co-morbidities. DPP-4 inhibitors are readily absorbed orally. Following oral ingestion, absorption occurs mainly in the small intestine, with median times to maximum (peak) plasma concentration ranging from 1 to 3 hours. The fraction of each dose absorbed ranges from approximately 30% with linagliptin to 75-87% for all others. Numerical differences in maximum (peak) plasma drug concentrations and areas under the plasma concentration-time curve among the DPP-4 inhibitors vary by an order of magnitude. However, functional capacity measured in terms of glucose-lowering ability remains comparable among all available DPP-4 inhibitors. Distribution of DPP-4 inhibitors is strongly influenced by both lipophilicity and protein binding. Apparent volumes of distribution (V(d)) for most agents range from 70 to 300 L. Linagliptin exhibits a V(d) of more than 1000 L, indicating widespread distribution into tissues. Binding to target proteins in plasma and peripheral tissues exerts a major influence upon broadening linagliptin distribution. DPP-4 inhibitor metabolism is widely variable, with reported terminal half-lives ranging from approximately 3 to more than 200 hours. Complex relationships between rates of receptor binding and dissociation appear to strongly influence the durations of action of those DPP-4 inhibitors with comparatively shorter half-lives. Durations of activity often are not reflective of clearance and, with the exception of vildagliptin which may be administered either once daily in the evening or twice daily, these medications are effective when used with a once-daily dosing schedule. Saxagliptin and, to a lesser extent, sitagliptin are largely metabolized by hepatic cytochrome P450 (CYP) 3A4 and 3A5 isoforms. With the exception of the primary hydroxylated metabolite of saxagliptin, which is 2-fold less potent than its parent molecule, metabolic products of hepatic biotransformation are minimally active and none appreciably contribute to either the therapeutic or the toxic effects of DPP-4 inhibitors. No DPP-4 inhibitor has been shown to inhibit or to induce hepatic CYP-mediated drug metabolism. Accordingly, the number of clinically significant drug-drug interactions associated with these agents is minimal, with only saxagliptin necessitating dose adjustment if administered concurrently with medications that strongly inhibit CYP3A4. Linagliptin undergoes enterohepatic cycling with a large majority (85%) of the absorbed dose eliminated in faeces via biliary excretion. Other DPP-4 inhibitors predominantly undergo renal excretion, with 60-85% of each dose eliminated as unchanged parent compound in the urine. Systematic reviews of clinical trials suggest that the overall efficacy of DPP-4 inhibitors in patients with type 2 diabetes generally is similar. Apart from these generalizations, pharmacokinetic distinctions that potentially influence product selection are tentative. When considered in total, data reviewed in this report suggest that the best overall balance between potency and the clinical pharmacokinetic characteristics of distribution, metabolism and elimination may be observed with linagliptin followed closely by vildagliptin, saxagliptin, sitagliptin and alogliptin.

Interventions for cardiovascular disease prevention

Cardiovascular disease prevention is a continuum that encompasses the life-course. This article discusses preventive strategies focusing on policy and clinical initiatives including primordial prevention (lifestyle changes involving smoking, diet and exercise), primary prevention (risk factor control), and secondary prevention (acute and chronic disease management). Combined use of all the three strategies can have an immediate and large impact on reducing CVD morbidity and mortality.

Evaluation of efficacy and tolerability of gliclazide and metformin combination: a multicentric study in patients with type 2 diabetes mellitus uncontrolled on monotherapy with sulfonylurea or metformin

The objective of this study was to compare the effects of gliclazide/metformin on glycemic control in patients with Type 2 diabetes mellitus uncontrolled on monotherapy with sulfonylurea or metformin. This was a prospective, open-labeled, multicentric study over 12 weeks. Patients who were diagnosed of Type 2 diabetes and were uncontrolled on monotherapy with oral hypoglycemic agents, including gliclazide and metformin, characterized by HbA1c 7% or greater and 10% or less and fasting plasma glucose (FPG) 140 mg/dL or greater were enrolled in this study. The treatment regimen was started at 80 mg gliclazide plus 500 mg metformin once a day and was titrated to the next dose level depending on the clinician's judgment, not exceeding a total daily dose of 320 mg gliclazide and 2000 mg metformin. Changes from baseline HbA1c, FPG, and postprandial glucose were examined. After 12-weeks treatment, the gliclazide + metformin combination showed improvement in metabolic control as assessed by changes in HbA1c, FPG, and postprandial glucose. The primary efficacy parameter, HbA1c, was significantly reduced to 7.35 ± 1.10 at the end of treatment from the baseline value (8.51 ± 0.77) (P < 0.001). A total of 84.35% of patients showed a 0.5% or greater reduction in HbA1c and 37.39% of patients reported less than 7% HbA1c at the end of therapy. FPG and postprandial glucose were significantly reduced at the end of therapy as compared with baseline values (P < 0.001). Moreover, the lipid profile was also improved during the treatment period. The addition of gliclazide to metformin is an effective treatment for patients inadequately controlled on sulfonylurea or metformin alone. A combination of gliclazide with metformin achieves good glycemic control and improves lipid levels with better tolerability profile.

Efficacy of a child-centred and family-based program in promoting healthy weight and healthy behaviors in Chinese American children: a randomized controlled study

OBJECTIVE

To examine the efficacy of an interactive, child-centred and family-based program in promoting healthy weight and healthy lifestyles in Chinese American children.

DESIGN

A randomized controlled study of a culturally sensitive behavioral intervention.

SUBJECTS

Sixty-seven Chinese American children (ages, 8-10 years; normal weight and overweight) and their families.

MEASUREMENTS

Anthropometry, blood pressure, measures of dietary intake, physical activity, knowledge and self-efficacy regarding physical activity and diet at baseline and 2, 6 and 8 months after baseline assessment.

RESULTS

Linear mixed modeling indicated a significant effect of the intervention in decreasing body mass index, diastolic blood pressure and fat intake while increasing vegetable and fruit intake, actual physical activity and knowledge about physical activity.

CONCLUSION

This interactive child-centred and family-based behavioral program appears feasible and effective, leading to reduced body mass index and improved overweight-related health behaviors in Chinese American children. This type of program can be adapted for other minority ethnic groups who are at high risk for overweight and obesity and have limited access to programs that promote healthy lifestyles.

Predictors of increased body mass index in Chinese children

A longitudinal study design was used to examine factors related to change of body mass index (BMI) over a 1-year period in 307 Chinese children, aged 7 and 8 years, in Taiwan. Standardized instruments were used to measure the children's food intake, physical activity/inactivity, and physical fitness, as well as maternal BMI. Results suggested that a high baseline BMI, poor aerobic capacity, and a high maternal BMI were significantly correlated with increased BMI at 12 months' follow-up. A higher baseline BMI, an overweight mother, increased television viewing and computer time, and poorer aerobic capacity were identified as predictors for weight gain in children (F=207.67; P<.001; adjusted R(2)=0.752). These findings suggest that health care providers need to include the family in children's health care visits and incorporate an assessment of maternal weight status and children's BMI status, activity levels, and aerobic capacity into patient care and education.

Measuring dietary acculturation in Japanese Americans with the use of confirmatory factor analysis of food-frequency data

BACKGROUND

Epidemiologic evidence suggests that dietary changes associated with acculturation to a Western diet may increase the risk of type 2 diabetes in Japanese Americans.

OBJECTIVE

We hypothesized that dietary acculturation patterns could be measured by confirmatory factor analysis (CFA) by using a culturally sensitive food-frequency questionnaire (FFQ). We examined the utility of the estimated factor scores by testing for associations with diabetes and 2 risk factors for diabetes-body mass index (BMI; in kg/m(2)) and C-reactive protein (CRP).

DESIGN

By using cross-sectional data from a sample of 219 Nisei (second-generation Japanese American; mean age 70 y) and 277 Sansei (third-generation Japanese American; mean age 42 y) participants in the Japanese American Family Study, we conducted CFA on 5 items characteristic of a Japanese diet and 4 items characteristic of a Western diet. The resulting factor scores were examined for associations with diabetes by using logistic regression and for associations with BMI and CRP by using linear regression.

RESULTS

CFA confirmed the presence of Japanese and Western food factors. The Nisei had a significantly higher average factor score for the Japanese food factor and significantly lower average factor score for the Western food factor than did the Sansei. In Sansei persons, but not in Nisei persons, the Western food factor score was significantly associated with plasma CRP concentration (P = 0.02), BMI (P = 0.02), and diabetes (P = 0.001).

CONCLUSIONS

In this Japanese American sample, dietary acculturation can be estimated by using CFA on FFQ data. Future studies should investigate the effects of dietary acculturation on disease risk independent of other lifestyle factors.

Body fat distribution and risk of diabetes among Chinese women

OBJECTIVE

To assess the relationship between measures of central and overall obesity and risk of diabetes.

DESIGN

Nested case-control study.

SETTING

Shanghai, China.

PARTICIPANTS

A total of 57 130 women were screened for diabetes at enrollment for the Shanghai Women's Health Study (SWHS), a population-based cohort study of Chinese women aged 40-70 y. In this study, 345 women diagnosed with diabetes and 2760 age-matched controls (eight controls per case), randomly selected from women who tested negative for urine glucose, were included.

RESULTS

Risk of diabetes increased significantly with increasing levels of obesity, particularly with measures of central obesity. Compared to those in the lowest quartile, women in the highest quartile of body mass index (BMI) (>/=26.57) and waist to hip ratio (WHR) (>/=0.855) had a 2.57-fold (95% CI 1.75-3.77) and a 6.05-fold (95% CI 4.05-9.04) increased risk of diabetes, respectively. The risk of diabetes was elevated with increasing WHR at all levels of BMI, while the positive association between BMI and diabetes was observed primarily among women with a low WHR. However, test for multiplicative interaction was not statistically significant.

CONCLUSIONS

Our data indicated that central obesity is a stronger risk factor for diabetes than overall obesity, suggesting that WHR may be a better indicator of risk of diabetes than BMI among Chinese women.

Rethinking diabetes prevention and control in racial and ethnic communities

The growing and disproportionate burden of type 2 diabetes experienced by racial and ethnic minority groups in the United States demands a refocusing of public health research and interventions if health outcomes are to improve. Public health research and practice must address the social production of diabetes, broaden the boundaries of how diabetes risk and causation are understood and articulated, and establish community health models that reflect the changing complexion and sociopolitical dynamics of contemporary urban communities. Relying on the traditional one-on-one clinical relationship that has characterized diabetes care in the past will not eliminate the diabetes epidemic in racial and ethnic communities.

Non-industrialised countries and affluence

The prevalence of type 2 diabetes is rising rapidly in all non-industrialised populations. By 2025, three-quarters of the world's 300 million adults with diabetes will be in non-industrialised countries, and almost a third in India and China alone. There is strong evidence that this epidemic has been triggered by social and economic development and urbanisation, which are associated with general improvements in nutrition and longevity, but also with obesity, reduced physical exercise and other diabetogenic factors. There is evidence too that fetal growth retardation and growth failure in infancy, both still widespread in non-industrialised populations, increase susceptibility to diabetes. An additional factor may be intergenerational effects of gestational diabetes occurring in mothers who grew poorly in early life and become obese as adults. Prevention of type 2 diabetes will require measures to promote exercise and reduce obesity in adults and children, alongside programmes to achieve healthy fetal and infant growth.

Ethnicity, childhood environment and atopic disorder

BACKGROUND

The International Study of Asthma and Allergies in Childhood (ISAAC) has demonstrated large differences in the prevalence of atopic disorders in children between different regions in the world. Populations with a higher standard of living and a more westernized lifestyle tend to have higher rates of atopy and asthma. Many hypotheses regarding environmental causes of atopic disorder focus on the early childhood environment.

OBJECTIVE

To study the influence of ethnicity and country of birth for the prevalence of atopic disorders.

METHODS

The prevalence of atopic disorders in Swedish residents born in Turkey and Chile, who settled in Sweden as adults in the 1980s, was compared with their own Swedish-born children and a sample of Swedish-born parents and their children in interview data from the Survey of Living Conditions in 1996. The study group included 1734 adults 27-60 years of age and their 2964 children aged 3-15.

RESULTS

The Chilean-born parents and their children had the highest risk for allergic asthma; adjusted odds ratios (ORs) 2.2 (1.2-4.0) and 2.7 (1.6-4.5), respectively, and allergic rhino-conjunctivitis; OR 1.6 (1.1-3) and 1.6 (1.1-2.5) in both groups, when compared with the Swedish-born parents and their children. The Turkish-born parents and their children had the lowest risk for allergic rhino-conjunctivitis; both groups had OR 0.6 (0. 4-0.9) and the children in this group also had the lowest risk for eczema; OR; 0.4 (0.3-0.7). The risk for all atopic disorders was lower in the Turkish group compared with the Chileans.

CONCLUSION

This study demonstrates that ethnicity is an important determinant of atopic disorder independent of the external childhood environment. The value of international comparisons of environment and risk for atopic disorders can be questioned until more is known about factors related to ethnicity, such as genetic susceptibility and diet, for the development of atopy.

Diabetes epidemic in newly westernized populations: is it due to thrifty genes or to genetically unknown foods?

Until a few decades ago, certain 'new-world' populations that kept to traditional dietary habits were virtually free from diabetes; then, after they began eating some foods that are common in Europe, the disease reached epidemic proportions. Europeans, by contrast, have a low rate of diabetes. To account for this paradox, it has been suggested that those new-world populations have a thrifty genotype, which would have conferred a selective advantage during the frequent famines of the past, while today it would be detrimental because the recently adopted foods are constantly available. Here it is proposed that thrifty genes are unlikely to exist. Both the diabetes epidemics that occur in newly westernized populations and the low rate of diabetes in Europeans can be explained by the hypothesis that Europeans, through millenary natural selection, have become adapted, albeit incompletely, to some diabetogenic foods for which humankind is genetically unequipped.