The significance of a positive family history in South African Indians with non-insulin-dependent diabetes (NIDDM)

Age at diagnosis of type 2 diabetes and cardiovascular risk factor profile: A pooled analysis

BACKGROUND

The diagnosis of type 2 diabetes (T2D) in younger adults, an increasingly common public health issue, is associated with a higher risk of cardiovascular complications and mortality, which may be due to a more adverse cardiovascular risk profile in individuals diagnosed at a younger age.

AIM

To investigate the association between age at diagnosis and the cardiovascular risk profile in adults with T2D.

METHODS

A pooled dataset was used, comprised of data from five previous studies of adults with T2D, including 1409 participants of whom 196 were diagnosed with T2D under the age of 40 years. Anthropometric and blood biomarker measurements included body weight, body mass index (BMI), waist circumference, body fat percentage, glycaemic control (HbA1c), lipid profile and blood pressure. Univariable and multivariable linear regression models, adjusted for diabetes duration, sex, ethnicity and smoking status, were used to investigate the association between age at diagnosis and each cardiovascular risk factor.

RESULTS

A higher proportion of participants diagnosed with T2D under the age of 40 were female, current smokers and treated with glucose-lowering medications, compared to participants diagnosed later in life. Participants diagnosed with T2D under the age of 40 also had higher body weight, BMI, waist circumference and body fat percentage, in addition to a more adverse lipid profile, compared to participants diagnosed at an older age. Modelling results showed that each one year reduction in age at diagnosis was significantly associated with 0.67 kg higher body weight [95% confidence interval (CI): 0.52-0.82 kg], 0.18 kg/m² higher BMI (95%CI: 0.10-0.25) and 0.32 cm higher waist circumference (95%CI: 0.14-0.49), after adjustment for duration of diabetes and other confounders. Younger age at diagnosis was also significantly associated with higher HbA1c, total cholesterol, low-density lipoprotein cholesterol and triglycerides.

CONCLUSION

The diagnosis of T2D earlier in life is associated with a worse cardiovascular risk factor profile, compared to those diagnosed later in life.

The association between prognosis of breast cancer and first-degree family history of breast or ovarian cancer: a systematic review and meta-analysis

Whether a positive family history of breast cancer or ovarian cancer (FHBOC) would affect the prognosis of breast cancer is still up for debate and further study. This meta-analysis was performed to clarify this issue. We reviewed two databases (PubMed and CNKI) for research articles published at any time from the inception of these databases to April 1, 2016 for articles detecting the impact of FHBOC on the prognosis of breast cancer. A meta-analysis was conducted to generated combined hazard ratios (HR) with 95% confidence intervals (CI) for overall survival (OS) and breast cancer-specific survival (BCSS). Eighteen studies were included in our qualitative analysis, with 15 studies ultimately part of the quantitative analysis. The pooled results demonstrated that a positive FHBOC was associated with better OS (0.89, 95% CI 0.83-0.95) and BCSS (0.90, 95% CI 0.82-0.99). In subgroup analyses, several subgroups (maximally adjusted studies, population based studies, high quality studies, family history of breast cancer, studies from Europe, studies from Asia, 1 affected relative, or tumor size > 2 cm), a positive first-degree FHBOC was associated with better prognosis of breast cancer. Notably, for those patients who underwent breast-conserving surgery, first-degree FHBOC was not a risk factor for OS (HR 1.08, 95% CI 0.53-2.21). Our meta-analysis demonstrated that a first-degree FHBOC was associated with better OS and BCSS in patients with breast cancer. These findings support that clinical management should not differ between women with and without FHBOC.

Review: Diabetes mellitus in South African Indians

Diabetes mellitus is common in the South Asian population residing in the Indian diaspora. Cardiovascular disease is a major cause of death in the Indians of South Africa. This study reviews the epidemiology and clinical pattern of diabetes mellitus in the South African Indian population from the available published literature. The concept of insulin resistance in the Indian population group appears to be interesting and has a novel approach towards explaining the high risk of cardiovascular disease. Dietary factors and physical inactivity could contribute to diabete mellitus.

Maternal history of diabetes is associated with increased cardiometabolic risk in Chinese

OBJECTIVE

Positive family history is associated with increased type 2 diabetes (T2D) risk, and reflects both genetic and environmental risks. Several studies have suggested an excess maternal transmission of T2D, although the underlying mechanism is unknown. We aimed to examine the association between maternal diabetes and cardiometabolic risk in the offspring.

METHODS

Parental history of diabetes and clinical data including anthropometric traits, fasting plasma glucose and insulin (FPG, FPI), blood pressure and lipid profile were collected from 2581 unrelated Chinese offspring (2026 adolescents from a population-based school survey and 555 adults from a community-based health screening programme). A subset of subjects (n=834) underwent oral glucose tolerance test to measure the glucose and insulin concentrations at 0, 15, 30, 60 and 120 min for evaluation of the areas under the curve (AUC) of glucose and insulin at 0-120 min, homoeostasis model assessment of insulin resistance (HOMA-IR) and bell-cell function, insulinogenic index, insulin sensitivity index (ISI) and oral disposition index (DI).

RESULTS

A positive parental history of diabetes was associated with increased risk of obesity (odd ratios (OR) (95% confidence interval (CI))=1.48 (1.10-2.00)), central obesity (OR (95% CI)=1.67 (1.21-2.32)), higher FPI, HOMA-IR, 2-h insulin, AUC of glucose at 0-120 min, triglycerides, reduced ISI and DI. Compared with individuals without parental diabetes, offspring with diabetic mother had significantly increased risk of obesity (OR (95% CI)=1.59 (1.07-2.35)), central obesity (OR (95% CI)=1.88 (1.23-2.88)), higher glucose levels and BP, were more insulin resistant but also had impaired first-phase insulin response and worse lipid profile. However, paternal history of diabetes had no effect on any of the studied traits, except higher body mass index, waist circumference in females and FPG.

CONCLUSIONS

Our findings suggested that maternal history of diabetes conferred increased risk of cardiometabolic abnormalities, and was associated with both insulin resistance and impaired first-phase insulin secretion. Further investigation into the mechanism of transgenerational diabetes is warranted.

Prevalence of type 2 diabetes mellitus and impaired glucose tolerance in the Kashmir Valley of the Indian subcontinent

This cross-sectional population survey was undertaken to determine the prevalence of type 2 diabetes and impaired glucose tolerance in subjects aged 40 years or more in Kashmir Valley, India. The study was carried out in two phases. In phase one, 6091 randomly selected subjects, 40 years or older, from all six districts of the valley were surveyed for prevalence of known diabetes mellitus. In phase two, 5083 subjects, 40 years or older, were screened with oral glucose tolerance test for prevalence of undiagnosed (asymptomatic) diabetes mellitus and impaired glucose tolerance. Abnormalities of carbohydrate intolerance were determined as recommended by WHO. Of 6091 subjects interviewed, 115 were known cases of diabetes mellitus with an overall prevalence of 1.89% (1.98% in males and 1.77% in females). Results of glucose tolerance test revealed that mean fasting as well as mean 2 h blood glucose was significantly more in females as compared to males (4.68+/-0.91 and 6.40+/-2.12 vs. 4.49+/-0.96 and 5.94+/-2.03 mmol/l, respectively, P < 0.0001). Of 5083 subjects who were subjected to glucose tolerance test (GTT), 627 (12.34%) had an abnormal test; with 411 (8.09%) having impaired glucose tolerance (IGT) and 216 (4.25%) having diabetes mellitus. The prevalence of IGT as well as of diabetes was significantly more in females as compared to males (P < 0.001). Subjects who had family history of diabetes had a significantly higher prevalence of abnormal GTT. Prevalence of known diabetes as well as that of abnormal GTT steadily increased with age, with a highest prevalence in the age group of > or = 70 years (P < 0.001). Obese subjects had a significantly higher basal as well as 2 h blood glucose in males as well as in females. Subjects with diabetes on GTT had a higher waist/hip ratio. Overall the prevalence of diabetes as well as IGT was significantly higher in the urban population. We conclude that 1.89% of the general population have known diabetes, 4.25% have undiagnosed diabetes and 8.09% have impaired glucose tolerance test; making the total load of abnormal glucose tolerance 14.23% in Kashmir Valley. In subjects greater than 40 years of age having a family history of diabetes, obesity, higher age (50 years or above), female sex, and urban origin have more chance (odds ratio: 4.65, 2.30, 1.87, 1.49 and 1.16, respectively) of developing abnormal glucose tolerance.