Ethnicity modifies the relation between fasting plasma glucose and HbA1c in Indians, Malays and Chinese.

AIMS: To study whether HbA(1c) , and its relationship with fasting plasma glucose, was significantly different among Chinese, Malays and Indians in Singapore. METHODS: A sample of 3895 individuals without known diabetes underwent detailed interview and health examination, including anthropometric and biochemical evaluation, between 2004 and 2007. Pearson's correlation, analysis of variance and multiple linear regression analyses were used to examine the influence of ethnicity on HbA(1c) . RESULTS: As fasting plasma glucose increased, HbA(1c) increased more in Malays and Indians compared with Chinese after adjustment for age, gender, waist circumference, serum cholesterol, serum triglyceride and homeostasis model assessment of insulin resistance (P-interaction < 0.001). This translates to an HbA(1c) difference of 1.1 mmol/mol (0.1%, Indians vs. Chinese), and 0.9 mmol/mol (0.08%, Malays vs. Chinese) at fasting plasma glucose 5.6 mmol/l (the American Diabetes Association criterion for impaired fasting glycaemia); and 2.1 mmol/mol (0.19%, Indians vs. Chinese) and 2.6 mmol/mol (0.24%, Malays vs. Chinese) at fasting plasma glucose 7.0 mmol/l, the diagnostic criterion for diabetes mellitus. CONCLUSIONS: Using HbA(1c) in place of fasting plasma glucose will reclassify different proportions of the population in different ethnic groups. This may have implications in interpretation of HbA(1c) results across ethnic groups and the use of HbA(1c) for diagnosing diabetes mellitus.

Insulin resistance is associated with a metabolic profile of altered protein metabolism in Chinese and Asian-Indian men.

AIMS/HYPOTHESIS: Insulin resistance (IR) is associated with obesity, but can also develop in individuals with normal body weight. We employed comprehensive profiling methods to identify metabolic events associated with IR, while controlling for obesity. METHODS: We selected 263 non-obese (BMI approximately 24 kg/m2) Asian-Indian and Chinese men from a large cross-sectional study carried out in Singapore. Individuals taking medication for diabetes or hyperlipidaemia were excluded. Participants were separated into lower and upper tertiles of IR based on HOMA indices of < or =1.06 or > or =1.93, respectively. MS-based metabolic profiling of acylcarnitines, amino acids and organic acids was combined with hormonal and cytokine profiling in all participants. RESULTS: After controlling for BMI, commonly accepted risk factors for IR, including circulating fatty acids and inflammatory cytokines, did not discriminate the upper and lower quartiles of insulin sensitivity in either Asian- Indian or Chinese men. Instead, IR was correlated with increased levels of alanine, proline, valine, leucine/isoleucine, phenylalanine, tyrosine, glutamate/glutamine and ornithine, and a cluster of branched-chain and related amino acids identified by principal components analysis. These changes were not due to increased protein intake by individuals in the upper quartile of IR. Increased abdominal adiposity and leptin, and decreased adiponectin and IGF-binding protein 1 were also correlated with IR. CONCLUSIONS/INTERPRETATION: These findings demonstrate that perturbations in amino acid homeostasis, but not inflammatory markers or NEFAs, are associated with IR in individuals of relatively low body mass.

Twin births in Singapore: a population-based study using the National Birth Registry.

INTRODUCTION: Twin studies are a most effective method to analyse gene and environment interactions. Using data from the Singapore National Registry of Births and Deaths (SNRBD), this paper describes the number of twin and multiple births among different ethnic populations in Singapore. MATERIALS AND METHODS: All births recorded in the SNRBD from 1 January 1986 to 31 December 2001 were analysed. Outcomes measured were twin and triple birth rates (per 1000 maternities) of the 3 main ethnic groups in Singapore (Chinese, Malays and Asian Indians). Further outcomes were calculated using Weinberg's differential rule to estimate the number of monozygotic and dizygotic twins. RESULTS: Overall twin birth rates have steadily increased across all ethnic groups (7 to 9/1000). The largest increase in multiple births among the ethnic groups were twins born to Asian Indian fathers (6.9 to 9.9/1000) and Malay mothers (5.9 to 9.8/1000). A significant difference in birth rates between the ethnic groups was found during the years 1994 to 1997, where Chinese parents had the lowest multiple birth rates and Asian Indians the highest. Estimation and ratios of monozygotic and dizygotic twin births differed among the ethnic groups: Asian Indians had the highest ratios, followed by the Chinese and, lastly, the Malays. CONCLUSION: The SNRBD has provided an overview of multiple births in Singapore, although the establishment of a national twin register would enable more detailed analysis of genetic and environmental effects in multiple births.

Cancer incidence in Singapore, 1998 to 1999.

The age-standardised incidence rates for all cancers for 1998-1999 were 235.0 per 100,000 in males and 199.8 per 100,000 in females. The corresponding rates for 1993-1997 were 233.1 per 100,000 in males and 198.1 per 100,000 in females. The greatest difference was for breast cancer in females with age-standardised incidence rates increasing from 46.1 to 53.1 cases per 100,000 persons per year between these time periods. There also appears to be a shift of the peak age-specific incidence for breast cancer from premenopausal to postmenopausal years over this period. This suggests that our breast cancer incidence pattern is rapidly becoming more similar to populations in the West.