Crystal Man Ying Lee

Indices of abdominal obesity are better discriminators of cardiovascular risk factors than BMI: a meta-analysis

OBJECTIVE To determine which simple index of overweight and obesity is the best discriminator of cardiovascular risk factors. STUDY DESIGN AND SETTING This is a meta-analysis of published literature. MEDLINE was searched. Studies that used receiver-operating characteristics (ROC) curve analysis and published area under the ROC curves (AUC) for overweight and obesity indices with hypertension, type-2 diabetes, and/or dyslipidemia were included. The AUC for each of the four indices, with each risk factor, was pooled using a random-effects model; male and female data were analyzed separately. RESULTS Ten studies met the inclusion criteria. Body mass index (BMI) was the poorest discriminator for cardiovascular risk factors. Waist-to-height ratio (WHtR) was the best discriminator for hypertension, diabetes, and dyslipidemia in both sexes; its pooled AUC (95% confidence intervals) ranged from 0.67 (0.64, 0.69) to 0.73 (0.70, 0.75) and from 0.68 (0.63, 0.72) to 0.76 (0.70, 0.81) in males and females, respectively. CONCLUSION Statistical evidence supports the superiority of measures of centralized obesity, especially WHtR, over BMI, for detecting cardiovascular risk factors in both men and women.

Coffee, decaffeinated coffee, and tea consumption in relation to incident type 2 diabetes mellitus: a systematic review with meta-analysis.

BACKGROUND Coffee consumption has been reported to be inversely associated with risk of type 2 diabetes mellitus. Similar associations have also been reported for decaffeinated coffee and tea. We report herein the findings of meta-analyses for the association between coffee, decaffeinated coffee, and tea consumption with risk of diabetes. METHODS Relevant studies were identified through search engines using a combined text word and MeSH (Medical Subject Headings) search strategy. Prospective studies that reported an estimate of the association between coffee, decaffeinated coffee, or tea with incident diabetes between 1966 and July 2009. RESULTS Data from 18 studies with information on 457 922 participants reported on the association between coffee consumption and diabetes. Six (N = 225 516) and 7 studies (N = 286 701) also reported estimates of the association between decaffeinated coffee and tea with diabetes, respectively. We found an inverse log-linear relationship between coffee consumption and subsequent risk of diabetes such that every additional cup of coffee consumed in a day was associated with a 7% reduction in the excess risk of diabetes relative risk, 0.93 [95% confidence interval, 0.91-0.95]) after adjustment for potential confounders. CONCLUSIONS Owing to the presence of small-study bias, our results may represent an overestimate of the true magnitude of the association. Similar significant and inverse associations were observed with decaffeinated coffee and tea and risk of incident diabetes. High intakes of coffee, decaffeinated coffee, and tea are associated with reduced risk of diabetes. The putative protective effects of these beverages warrant further investigation in randomized trials.

Height, wealth, and health: An overview with new data from three longitudinal studies

This overview, based on a literature review and new data from the three cohorts (Whitehall Studies I and II, and the Vietnam Experience Study), has four objectives: (a) to outline the major determinants of height, so providing an indication as to what exposures this characteristic may capture; (b) to summarise, by reviewing reports from large scale studies, the relation between adult height and a range of disease outcomes--both somatic and psychiatric--with particular emphasis on coronary heart disease (CHD) and stroke; (c) to discuss why these relationships may exist, in particular, the role, if any, of socioeconomic position in explaining the apparent associations; and, finally (d) to outline future research directions in this field. The large majority of evidence for predictors of height, and its health consequences, comes from observational studies. While genetic predisposition is a major determinant of height, secular rises in childhood and adult stature across successive birth cohorts suggest that early life environment also has an important impact. Plausible non-genetic determinants of height include nutrition, illness, socioeconomic status, and psychosocial stress. Evidence for an association between height and a series of health endpoints is accumulating. Thus, shorter people appear to experience increased risk of CHD, and these associations appear to be independent of socioeconomic position and other potentially confounding variables. For stroke, and its sub-types, findings are less clear. In contrast to CHD, some cancers, such as carcinoma of the colorectum, prostate, breast (in women), central nervous system, skin, endometrium, thyroid and blood (haematopoietic) are more common in taller people. While height may be negatively related to the risk of completed suicide, conclusions about the links between stature and other health endpoints is problematic given the paucity of evidence, which should be addressed. Ultimately, for want of better data, investigators in this area have used height as a proxy for a range of pre-adult exposures. In future, research should aim to explore the predictive capacity of direct measures of diet, psychosocial stress, childhood chronic illness and so on, rather than focus on height or its components. The problem is that extended follow-up of child cohorts with such data are required, and studies which hold these data are not currently available, although several are either maturing to the point where they offer sufficient clinical outcomes to facilitate analyses or are in the advanced planning stage.

Hypertension: its prevalence and population-attributable fraction for mortality from cardiovascular disease in the Asia-Pacific region.

Objective About half of the worlds burden of cardiovascular disease is carried by countries in the Asia-Pacific region. This study aimed to quantify the contribution of hypertension to cardiovascular diseases (CVD) at the country level, by calculating the sex-specific, population-attributable fractions (PAFs) for fatal ischaemic heart disease (IHD) and stroke (haemorrhagic and ischaemic) for the World Health Organization Western Pacific and South-east Asian regions. Methods The most recent sex-specific prevalence data on hypertension were sought. Age-adjusted hazard ratio (HR) estimates for fatal IHD and stroke associated with hypertension were obtained using Cox analyses of individual participant cohort data from 600 000 adult participants in the Asia-Pacific Cohort Studies Collaboration. HR estimates and prevalence were then used to calculate sex-specific PAFs for fatal IHD and stroke, by country. Results In 15 countries with available data, the prevalence of hypertension ranged from 5–47% in men and from 7–38% in women. Overall, the fraction of IHD attributable to hypertension ranged from 4–28% in men and from 8–39% in women. Corresponding ranges for haemorrhagic stroke were 18–66% and 15–49%, and for ischaemic stroke were 8–44% and 12–45%. Conclusions In the Asia-Pacific region, up to 66% of some subtypes of CVD can be attributed to hypertension, underscoring the immense impact that blood pressure- lowering strategies could have in this populous region.

Glycemic Thresholds for Diabetes-Specific Retinopathy: Implications for Diagnostic Criteria for Diabetes

OBJECTIVE To re-evaluate the relationship between glycemia and diabetic retinopathy. RESEARCH DESIGN AND METHODS We conducted a data-pooling analysis of nine studies from five countries with 44,623 participants aged 20–79 years with gradable retinal photographs. The relationship between diabetes-specific retinopathy (defined as moderate or more severe retinopathy) and three glycemic measures (fasting plasma glucose [FPG; n = 41,411], 2-h post oral glucose load plasma glucose [2-h PG; n = 21,334], and A1C [n = 28,010]) was examined. RESULTS When diabetes-specific retinopathy was plotted against continuous glycemic measures, a curvilinear relationship was observed for FPG and A1C. Diabetes-specific retinopathy prevalence was low for FPG <6.0 mmol/l and A1C <6.0% but increased above these levels. Based on vigintile (20 groups with equal numbers) distributions, glycemic thresholds for diabetes-specific retinopathy were observed over the range of 6.4–6.8 mmol/l for FPG, 9.8–10.6 mmol/l for 2-h PG, and 6.3–6.7% for A1C. Thresholds for diabetes-specific retinopathy from receiver-operating characteristic curve analyses were 6.6 mmol/l for FPG, 13.0 mmol/l for 2-h PG, and 6.4% for A1C. CONCLUSIONS This study broadens the evidence based on diabetes diagnostic criteria. A narrow threshold range for diabetes-specific retinopathy was identified for FPG and A1C but not for 2-h PG. The combined analyses suggest that the current diabetes diagnostic level for FPG could be lowered to 6.5 mmol/l and that an A1C of 6.5% is a suitable alternative diagnostic criterion.

The Burden of Overweight and Obesity in the Asia-Pacific Region

The rise in the prevalence of overweight and obesity (body mass index ≥25 kg m−2) is, in part, a negative consequence of the increasing economic developments of many lower‐ and middle‐income countries in the Asia–Pacific region. To date, there has been no systematic quantification of the scale of the problem in countries of this region. From the most recent nationally representative estimates for the prevalence of overweight and obesity in 14 countries of the region, it is apparent that overweight and obesity is endemic in much of the region, prevalence ranging from less than 5% in India to 60% in Australia. Moreover, although the prevalence in China is a third of that in Australia, the increase in prevalence in China over the last 20 years was 400% compared with 20% in Australia. In addition, across various countries in the region, the population attributable fractions because of overweight and obesity ranged from 0.8% to 9.2% for coronary heart disease mortality, 0.2% to 2.9% for haemorrhagic stroke mortality, and 0.9% to 10.2% for ischaemic stroke mortality. These results indicate that consequences of overweight and obesity for health and the economy of many of these countries are likely to increase in coming years.

Trends in overweight and obesity over 22 years in a large adult population: the HUNT Study, Norway

Some reports indicate that the obesity epidemic may be slowing down or halting. We followed body mass index (BMI) and waist circumference (WC) in a large adult population in Norway (n = 90 000) from 1984–1986 (HUNT1) through 1995–1997 (HUNT2) to 2006–2008 (HUNT3) to study whether this is occurring in Norway. Height and weight were measured with standardized and identical methods in all three surveys; WC was also measured in HUNT2 and HUNT3. In the three surveys, mean BMI increased from 25.3 to 26.5 and 27.5 kg m−2 in men and from 25.1 to 26.2 and 26.9 kg m−2 in women. Increase in prevalence of obesity (BMI ≥ 30 kg m−2) was greater in men (from 7.7 to 14.4 and 22.1%) compared with women (from 13.3 to 18.3 and 23.1%). In contrast, women had a greater increase in abdominal obesity (WC ≥ 102 cm for men and WC ≥ 88 cm for women). There was a continuous shift in the distribution curve of BMI and WC to the right, demonstrating that the increase in body weight was occurring in all weight groups, but the increase of obesity was greatest in the youngest age groups. Our data showed no signs of a halt in the increase of obesity in this representative Norwegian population.

Adult height and the risks of cardiovascular disease and major causes of death in the Asia-Pacific region: 21 000 deaths in 510 000 men and women

BACKGROUND In Caucasian populations, adult height is inversely associated with cardiovascular disease (CVD) risk and positively related to some cancers. However, there are few data from Asian populations and from women. We sought to determine the sex- and region-specific associations between height and cardiovascular outcomes, and deaths due to cancer, respiratory and injury in populations from the Asia-Pacific region. METHODS Thirty-nine studies from the Asia Pacific Cohort Studies Collaboration database were included. We used Cox proportional hazard regression models to estimate the associations between height and pre-specified outcomes. RESULTS A total of 510,800 participants with 21,623 deaths were included. Amongst men, inverse linear associations were observed between height and coronary heart disease (CHD), stroke, CVD, injury and total mortality. The hazard ratios [95% confidence intervals, (CI)] for a 1-SD (= 6 cm) increment in height ranged from 0.85 (0.80-0.91) for injury to 0.97 (0.95-0.98) for total mortality. Similar trends were found between height and CHD, haemorrhagic stroke and CVD in women. A positive linear association was observed between height and cancer mortality. For each standard deviation greater height, the risk of cancer was increased by 5% (2-8%) and 9% (5-14%) in men and women, respectively. No regional difference was observed between Asian and Australasian cohorts. Adjusting for markers of education did not alter the results. CONCLUSIONS The opposing relationships of height with CVD and cancer suggest that care is required in setting national policies on childhood nutrition lest they have unintended consequences on the incidence of major non-communicable diseases.

The fraction of ischaemic heart disease and stroke attributable to smoking in the WHO Western Pacific and South-East Asian regions

Background: Tobacco will soon be the biggest cause of death worldwide, with the greatest burden being borne by low and middle-income countries where 8/10 smokers now live. Objective: This study aimed to quantify the direct burden of smoking for cardiovascular diseases (CVD) by calculating the population attributable fractions (PAF) for fatal ischaemic heart disease (IHD) and stroke (haemorrhagic and ischaemic) for all 38 countries in the World Health Organization Western Pacific and South East Asian regions. Design and subjects: Sex-specific prevalence of smoking was obtained from existing data. Estimates of the hazard ratio (HR) for IHD and stroke with smoking as an independent risk factor were obtained from the ∼600 000 adult subjects in the Asia Pacific Cohort Studies Collaboration (APCSC). HR estimates and prevalence were then used to calculate sex-specific PAF for IHD and stroke by country. Results: The prevalence of smoking in the 33 countries, for which relevant data could be obtained, ranged from 28–82% in males and from 1–65% in females. The fraction of IHD attributable to smoking ranged from 13–33% in males and from <1–28% in females. The percentage of haemorrhagic stroke attributable to smoking ranged from 4–12% in males and from <1–9% in females. Corresponding figures for ischaemic stroke were 11–27% in males and <1–22% in females. Conclusions: Up to 30% of some cardiovascular fatalities can be attributed to smoking. This is likely an underestimate of the current burden of smoking on CVD, given that the smoking epidemic has developed further since many of the studies were conducted.

The cost of diabetes in adults in Australia

AIMS To assess and compare costs associated with diabetes and lesser degrees of glucose intolerance in Australia. METHODS The Australian Diabetes, Obesity and Lifestyle study collected data on the use of health services and health related expenditure in 2004-2005. Complications data were collected through physical examination and biochemical tests or questionnaire. Data were available on 6101 participants. Age- and sex-adjusted direct healthcare costs, direct non-healthcare costs and government subsidies were estimated according to glucose tolerance status. RESULTS Annual direct per person costs were A