The Association between the History of Cardiovascular Diseases and Chronic Low Back Pain in South Koreans: A Cross-Sectional Study

Background

Cardiovascular disease and related risk factors have been suggested as a mechanism leading to atherosclerosis of the lumbar vessels and consequent lumbar pain or sciatica. But there is continued controversy concerning its generalization. This study examined whether cardiovascular disease or its risk factors were associated with chronic low back pain (cLBP) in Koreans.

Methods

Health surveys and examinations were conducted on a nationally representative sample (n = 23,632) of Koreans. A total of 13,841 eligible participants (aged 20 to 89 years) were examined to determine the association between cardiovascular disease, the Framingham risk score, major cardiovascular risk factors (blood pressure, diabetes, cholesterol, and smoking habits) and chronic LBP.

Results

The total prevalence of cLBP was 16.6% (men: 10.8%, women: 21.1%) and that in patients with a history of cardiovascular diseases was 36.6% (men: 26.5%, women: 47.1%). The results showed that patients’ medical history of cardiovascular disease was significantly associated with cLBP in both men and women when adjusted for covariates (men: OR 2.16; 95%CI 1.34∼3.49; women: OR 2.26; 95%CI 1.51∼3.38). No association was observed between cLBP and the Framingham risk score, medication for hyperlipemia, hypertension, diabetes, and major cardiovascular risk factors (systolic blood pressure, total cholesterol, high density lipoprotein cholesterol, triglycerides, glucose and smoking habits) in either men or women.

Conclusions

The prevalence of cLBP is correlated to a history of cardiovascular disease, but not to the major cardiovascular risk factors from the Framingham study. Further studies on whether these results were affected by psychological factors in patients with a history of cardiovascular diseases or whether new potential risk factors from the artery atherosclerosis hypothesis applying to Koreans exist are needed.     

Job Strain,Health and Sickness Absence: Results from the Hordaland Health Study

Objectives

While it is generally accepted that high job strain is associated with adverse occupational outcomes, the nature of this relationship and the causal pathways involved are not well elucidated. We aimed to assess the association between job strain and long-term sickness absence (LTSA), and investigate whether any associations could be explained by validated health measures.

Methods

Data from participants (n = 7346) of the Hordaland Health Study (HUSK), aged 40–47 at baseline, were analyzed using multivariate Cox regression to evaluate the association between job strain and LTSA over one year. Further analyses examined whether mental and physical health mediated any association between job strain and sickness absence.

Results

A positive association was found between job strain and risk of a LTSA episode, even controlling for confounding factors (HR = 1.64 (1.36–1.98); high job strain exposure accounted for a small proportion of LTSA episodes (population attributable risk 0.068). Further adjustments for physical health and mental health individually attenuated, but could not fully explain the association. In the fully adjusted model, the association between high job strain and LTSA remained significant (HR = 1.30 (1.07–1.59)).

Conclusion

High job strain increases the risk of LTSA. While our results suggest that one in 15 cases of LTSA could be avoided if high job strain were eliminated, we also provide evidence against simplistic causal models. The impact of job strain on future LTSA could not be fully explained by impaired health at baseline, which suggests that factors besides ill health are important in explaining the link between job strain and sickness absence.     

Association between Voluntary/Involuntary Job Loss and the Development of Stroke or Cardiovascular Disease: A Prospective Study of Middle-Aged to Older Workers in a Rapidly Developing Asian Country

Background

The aim of this research was to investigate the association between job loss and the development of stroke or cardiovascular disease among middle-aged to older individuals in Korea. We also examined how this relationship was modified by gender and the nature of the job loss.

Methods

This study used samples from the first- to fourth-wave datasets from the Korean Longitudinal Study of Aging (KLoSA), which were collected in 2006, 2008, 2010, and 2012. The study collected data from a total of 10,254 subjects aged ≥45 years at baseline. After applying exclusion criteria, the final sample size for analysis consisted of 4,000 individuals. Information about employment status, development of stroke or cardiovascular disease, and covariates (age, income level, and behavioral factors) was obtained. Cox proportional hazards models were used to evaluate the association between voluntary/involuntary job loss and the development of stroke or cardiovascular disease. We performed these analyses separately according to disease, gender, and the nature of the job loss.

Results

Involuntary job loss significantly increased the risk of stroke or cardiovascular disease among males (adjusted hazard ratio [HR] = 3.560, 95% confidence interval [CI] = 2.055–6.168). Voluntary retirement also increased the risk of cardiovascular disease or stroke among males (adjusted HR = 2.879, 95% CI = 1.533–5.409). Job loss was more closely associated with stroke than with cardiovascular disease (stroke, adjusted HR = 6.208, 95% CI = 2.417–15.943; cardiovascular disease, adjusted HR = 2.768, 95% CI = 1.402–5.465).

Conclusion

Our findings suggest that both voluntary retirement and involuntary job loss increase the risk for stroke or cardiovascular disease in middle-aged to older individuals, especially males.     

Associations of job strain and lifestyle risk factors with risk of coronary artery disease: a meta-analysis of individual participant data

Background:

It is unclear whether a healthy lifestyle mitigates the adverse effects of job strain on coronary artery disease. We examined the associations of job strain and lifestyle risk factors with the risk of coronary artery disease.

Methods:

We pooled individual-level data from 7 cohort studies comprising 102 128 men and women who were free of existing coronary artery disease at baseline (1985–2000). Questionnaires were used to measure job strain (yes v. no) and 4 lifestyle risk factors: current smoking, physical inactivity, heavy drinking and obesity. We grouped participants into 3 lifestyle categories: healthy (no lifestyle risk factors), moderately unhealthy (1 risk factor) and unhealthy (2–4 risk factors). The primary outcome was incident coronary artery disease (defined as first nonfatal myocardial infarction or cardiac-related death).

Results:

There were 1086 incident events in 743 948 person-years at risk during a mean follow-up of 7.3 years. The risk of coronary artery disease among people who had an unhealthy lifestyle compared with those who had a healthy lifestyle (hazard ratio [HR] 2.55, 95% confidence interval [CI] 2.18–2.98; population attributable risk 26.4%) was higher than the risk among participants who had job strain compared with those who had no job strain (HR 1.25, 95% CI 1.06–1.47; population attributable risk 3.8%). The 10-year incidence of coronary artery disease among participants with job strain and a healthy lifestyle (14.7 per 1000) was 53% lower than the incidence among those with job strain and an unhealthy lifestyle (31.2 per 1000).

Interpretation:

The risk of coronary artery disease was highest among participants who reported job strain and an unhealthy lifestyle; those with job strain and a healthy lifestyle had half the rate of disease. A healthy lifestyle may substantially reduce disease risk among people with job strain.Psychosocial work stress, denoted by job strain, is associated with an elevated risk of coronary artery disease.^1–7 This association is apparent across strata of sex, age, socioeconomic status and region, and it does not appear to be completely explained by confounding.⁷ For many people, avoidance of stress at work is unrealistic. The absence of strong evidence for effective interventions to reduce job strain therefore raises the challenge of identifying additional approaches for dealing with the health impact of stress in the workplace.Guidelines for the prevention of heart disease emphasize the importance of a healthy lifestyle — physical activity, a healthy diet (and healthy weight) and not smoking — in lowering disease risk.^8–11 Whether a healthy lifestyle offsets the deleterious impact of job strain on coronary artery disease remains unclear. A straightforward approach to test this hypothesis would involve comparing the rates of coronary artery disease among people with job strain and an unhealthy lifestyle with the rates among those with job strain and a healthy lifestyle. If a marked difference is apparent, one would consider a healthy lifestyle to be the likely factor contributing to the reduced risk among those with job strain. However, such stratifications require a large, well-characterized dataset, which to date has been lacking. We pooled individual-level data for more than 100 000 men and women participating in 7 cohort studies to examine the combined associations of job strain and lifestyle with risk of coronary artery disease.     

Salt intake and mental distress among rural community-dwelling Japanese men

Background

Activated mineralocorticoid receptors influence the association between daily salt intake and blood pressure. A relatively low mineralocorticoid receptor function is reported to be a risk for mental distress such as depression. Since mental distress is also a known risk for hypertension and cardiovascular disease, understanding of the association between estimated daily salt intake and mental distress contributing to hypertension is important for risk estimation for cardiovascular disease. However, no single study has reported this association.

Methods

We conducted a cross-sectional study of 1014 Japanese men undergoing general health check-ups. Mental distress was diagnosed as a Kessler 6 scale score ≥5. We also classified mental distress by levels of hypertension. Estimated daily salt intake was calculated from a causal urine specimen.

Results

Independent from classical cardiovascular risk factors and thyroid disease, we found a significant inverse association between estimated daily salt intake and mental distress. When we analyzed for mental distress and hypertension, we also found a significant association. With the reference group being the lowest tertiles of estimated daily salt intake, the multivariable odds ratios (ORs) of mental distress and mental distress with hypertension for the highest tertiles were 0.50 (0.29–0.88) and 0.46 (0.22–0.96).

Conclusions

Lower estimated daily salt intake is a significant risk of mental distress for rural community-dwelling Japanese men. Since depression is reported to be associated with cardiovascular disease, risk estimation for the lower intake of salt on mental distress, especially for mental distress with hypertension, may become an important tool to prevent cardiovascular disease.     

Cardiometabolic Risk Profiles Associated with Chronic Complications in Overweight and Obese Type 2 Diabetes Patients in South China

Background

Type 2 diabetes is often accompanied by altered cardiometabolic risk profiles, including abdominal obesity, hypertension, and dyslipidaemia. The association of altered cardiometabolic risk profiles with chronic complications of diabetes is not well investigated.

Methods

We recruited 2954 type 2 diabetes patients with a body mass index ≥25 kg/m² who visited the diabetes clinics of 62 hospitals in 21 cities in Guangdong province of China from August 2011 to March 2012. Demographic characteristics, personal and family medical histories, and data on chronic complications of diabetes were collected. Clinical examinations and laboratory assessment were conducted.

Results

Abdominal obesity was found in 91.6% of the study population, elevated blood pressure in 78.3%; elevated serum triacylglycerols in 57.8%, and reduced serum HDL-C in 55.9%. Among the cardiometabolic risk factors, elevated blood pressure was significantly associated with almost all the chronic complications of diabetes. After adjusting for age, gender, duration of diabetes, and HbA1c, elevated blood pressure was significantly associated with diabetic retinopathy (OR 1.63, 95% CI: 1.22–2.19), diabetic nephropathy (OR 3.16, 95% CI: 2.25–4.46), cardiovascular disease (OR 2.71, 95% CI: 1.70–4.32), and stroke (OR 1.90, 95% CI: 1.15–3.12). Abdominal adiposity was significantly associated with diabetic nephropathy (OR 1.39, 95% CI: 1.11–1.74). Elevated triacylglycerols was significantly associated with diabetic retinopathy (OR 1.29, 95% CI: 1.05–1.58) and diabetic nephropathy (OR 1.30, 95% CI: 1.05–1.58). Reduced HDL-C was significantly associated with stroke (OR 1.41, 95% CI: 1.05–1.88).

Conclusions

Altered cardiometabolic risk profiles, and elevated blood pressure in particular, were significantly associated with chronic complications in overweight and obese patients with type 2 diabetes. Future studies on the prevention of chronic complications of diabetes might make lowering blood pressure a primary target.     

Skin Autofluorescence,a Non-Invasive Marker for AGE Accumulation,Is Associated with the Degree of Atherosclerosis

Introduction

Advanced glycation endproducts (AGEs) may be involved in the development of atherosclerosis, beyond diabetes and renal disease. Skin autofluorescence (AF) is a non-invasive marker for AGEs. We examined whether skin AF is increased in (subclinical) atherosclerosis and associated with the degree of atherosclerosis independent of diabetes and renal function.

Methods

A cross-sectional study of 223 patients referred for primary (n = 163) or secondary (n = 60) prevention between 2006 and 2012 was performed. Skin AF was measured using the AGE-Reader. Ultrasonography was used to assess plaques in carotid and femoral arteries and computed tomography for the calculation of the coronary artery calcium score (CACS; in primary prevention only). Primary prevention patients were divided into a group with subclinical atherosclerosis defined as >1 plaque or CACS>100 (n = 67; age 53 year [interquartile range 48–56]; 49% male) and without (controls; 96; 43 [38–51]; 55%). Secondary prevention were patients with peripheral arterial disease (60; 64 [58–70]; 73%).

Results

Skin AF was higher in subclinical and clinical atherosclerosis compared with controls (skin AF 2.11 [interquartile range 1.83–2.46] and 2.71 [2.15–3.27] vs. 1.87 [1.68–2.12] respectively; P = 0.005 and <0.001). In a multivariate analysis, the association of skin AF with the atherosclerosis categories was independent of age, sex, diabetes, presence of the metabolic syndrome, Framingham Risk Score, and renal function. Skin AF correlated with most cardiovascular risk factors, Framingham risk score, and IMT and CACS.

Conclusions

Skin AF is increased in documented subclinical and clinical atherosclerosis, independent of known risk factors such as diabetes and renal disease. These data suggest that AGEs may be associated with the burden of atherosclerosis and warrant a prospective study to investigate its clinical usability as a risk assessment tool for primary prevention.     

Depression and Risk of Mortality in People with Diabetes Mellitus: A Systematic Review and Meta-Analysis

Objective

To examine the association between depression and all-cause and cardiovascular mortality in people with diabetes by systematically reviewing the literature and carrying out a meta-analysis of relevant longitudinal studies.

Research Design and Methods

PUBMED and PSYCINFO were searched for articles assessing mortality risk associated with depression in diabetes up until August 16, 2012. The pooled hazard ratios were calculated using random-effects models.

Results

Sixteen studies met the inclusion criteria, which were pooled in an overall all-cause mortality estimate, and five in a cardiovascular mortality estimate. After adjustment for demographic variables and micro- and macrovascular complications, depression was associated with an increased risk of all-cause mortality (HR = 1.46, 95% CI = 1.29–1.66), and cardiovascular mortality (HR = 1.39, 95% CI = 1.11–1.73). Heterogeneity across studies was high for all-cause mortality and relatively low for cardiovascular mortality, with an I-squared of respectively 78.6% and 39.6%. Subgroup analyses showed that the association between depression and mortality not significantly change when excluding three articles presenting odds ratios, yet this decreased heterogeneity substantially (HR = 1.49, 95% CI = 1.39–1.61, I-squared = 15.1%). A comparison between type 1 and type 2 diabetes could not be undertaken, as only one study reported on type 1 diabetes specifically.

Conclusions

Depression is associated with an almost 1.5-fold increased risk of mortality in people with diabetes. Research should focus on both cardiovascular and non-cardiovascular causes of death associated with depression, and determine the underlying behavioral and physiological mechanisms that may explain this association.     

Racial Discrimination & Cardiovascular Disease Risk: My Body My Story Study of 1005 US-Born Black and White Community Health Center Participants (US)

Objectives

To date, limited and inconsistent evidence exists regarding racial discrimination and risk of cardiovascular disease (CVD).

Methods

Cross-sectional observational study of 1005 US-born non-Hispanic black (n = 504) and white (n = 501) participants age 35–64 randomly selected from community health centers in Boston, MA (2008–2010; 82.4% response rate), using 3 racial discrimination measures: explicit self-report; implicit association test (IAT, a time reaction test for self and group as target vs. perpetrator of discrimination); and structural (Jim Crow status of state of birth, i.e. legal racial discrimination prior 1964).

Results

Black and white participants both had adverse cardiovascular and socioeconomic profiles, with black participants most highly exposed to racial discrimination. Positive crude associations among black participants occurred for Jim Crow birthplace and hypertension (odds ratio (OR) 1.92, 95% confidence interval (CI) 1.28, 2.89) and for explicit self-report and the Framingham 10 year CVD risk score (beta  = 0.04; 95% CI 0.01, 0.07); among white participants, only negative crude associations existed (for IAT for self, for lower systolic blood pressure (SBP; beta  = −4.86; 95% CI −9.08, −0.64) and lower Framingham CVD score (beta  = −0.36, 95% CI −0.63, −0.08)). All of these associations were attenuated and all but the white IAT-Framingham risk score association were rendered null in analyses that controlled for lifetime socioeconomic position and additional covariates. Controlling for racial discrimination, socioeconomic position, and other covariates did not attenuate the crude black excess risk for SBP and hypertension and left unaffected the null excess risk for the Framingham CVD score.

Conclusion

Despite worse exposures among the black participants, racial discrimination and socioeconomic position were not associated, in multivariable analyses, with risk of CVD. We interpret results in relation to constrained variability of exposures and outcomes and discuss implications for valid research on social determinants of health.     

Resting Heart Rate and Risk of Cardiovascular Diseases and All-Cause Death: The Kailuan Study

Background

Resting heart rate (RHR) predicts both cardiovascular and noncardiovascular death in different populations. However, the results of the association between RHR and cardiovascular diseases (CVDs) are inconsistent, especially for each subtype of CVDs.

Objective

The aim of this study was to prospectively explore the relationship between RHR and CVDs including myocardial infarction (MI), ischemic stroke, and hemorrhagic stroke and all-cause death in a general population.

Methods

The Kailuan study is a prospective longitudinal cohort study on cardiovascular risk factors and cardiovascular or cerebrovascular events. Hazard ratio (HR) with 95% confidence intervals (CI) were calculated using Cox regression modeling.

Results

We analyzed 92,562 participants (18–98 years old) in the Kailuan Study. CVDs were developed in 1,903 people during follow-ups. In multivariate analysis with adjustment for major traditional cardiovascular risk factors, HRs of the highest quintile group compared with the lowest quintile group of RHR for all-cause CVDs, MI, any stroke, ischemic stroke, hemorrhagic stroke, and all-cause death were 1.03 (95% CI, 0.98–1.07), 1.10 (95% CI, 1.01–1.20), 1.01 (95% CI, 0.97–1.06), 1.02 (95% CI, 0.96–1.07), 1.01 (95% CI, 0.92–1.11) and 1.18, (95% CI, 1.13–1.23), respectively.

Conclusions

The elevated RHR was independently associated with the increased risk for MI and all-cause death, but not for all-cause CVDs, any stroke, ischemic stroke, nor hemorrhagic stroke. This indicates that the elevated RHR might be a risk marker for MI and all-cause death in general populations.     

Uric Acid as a Risk Factor for Cardiovascular Disease and Mortality in Overweight/Obese Individuals

Background

The predictive value of serum uric acid (SUA) for adverse cardiovascular events among obese and overweight patients is not known, but potentially important because of the relation between hyperuricaemia and obesity.

Methods

The relationship between SUA and risk of cardiovascular adverse outcomes (nonfatal myocardial infarction, nonfatal stroke, resuscitated cardiac arrest or cardiovascular death) and all-cause mortality, respectively, was evaluated in a post-hoc analysis of the Sibutramine Cardiovascular OUTcomes (SCOUT) trial. Participants enrolled in SCOUT were obese or overweight with pre-existing diabetes and/or cardiovascular disease (CVD). Cox models were used to assess the role of SUA as an independent risk factor.

Results

9742 subjects were included in the study; 83.6% had diabetes, and 75.1% had CVD. During an average follow-up time of 4.2 years, 1043 subjects had a primary outcome (myocardial infarction, resuscitated cardiac arrest, stroke, or cardiovascular death), and 816 died. In a univariate Cox model, the highest SUA quartile was associated with an increased risk of cardiovascular adverse outcomes compared with the lowest SUA quartile in women (hazard ratio [HR]: 1.59; 95% confidence interval [CI]: 1.20–2.10). In multivariate analyses, adjusting for known cardiovascular risk factors the increased risk for the highest SUA quartile was no longer statistically significant among women (HR: 0.99; 95% CI: 0.72–1.36) nor was it among men. Analyses of all-cause mortality found an interaction between sex and SUA. In a multivariate Cox model including women only, the highest SUA quartile was associated with an increased risk in all-cause mortality compared to the lowest SUA quartile (HR: 1.51; 95% CI: 1.08–2.12). No relationship was observed in men (HR: 1.06; 95% CI: 0.82–1.36).

Conclusion

SUA was not an independent predictor of cardiovascular disease and death in these high-risk overweight/obese people. However, our results suggested that SUA was an independent predictor of all-cause mortality in women.     

Association between Adiponectin Concentrations and Cardiovascular Disease in Diabetic Patients: A Systematic Review and Meta-Analysis

Background

This systematic review and meta-analysis of prospective studies evaluates the association between adiponectin concentrations and risk of cardiovascular disease (CVD) in individuals with diabetes mellitus (DM).

Methods

PubMed and Embase were searched for prospective studies on the association of adiponectin concentrations and risk of CVD up to June 2013. Random-effect model was selected to pool the relative risk (RR) and 95% CI.

Results

Five prospective cohort studies and one nested case-control studies met the included criterion. The estimated summary RR and 95% CI of five prospective cohort studies for type 2 diabetes comparing top vs low tertile of adiponectin concentrations was 0.99 (95% CI: 0.67–1.45), with significant heterogeneity between studies (p = 0.037, I ² = 60.9%). This heterogeneity was explained by one study conducted in Korean.

Conclusions

This study represents the first meta-analysis between adiponectin levels and CVD in diabetic patients and indicated no association was found. This result should be verified further by large sample size, long duration of follow-up, and well-designed prospective clinical trials.     

Inverse Association between Serum Bilirubin Levels and Arterial Stiffness in Korean Women with Type 2 Diabetes

Background

Considerable evidence suggests that bilirubin is a potent physiologic antioxidant that may provide important protection against cardiovascular disease (CVD) and inflammation. We investigated the relationship between serum total bilirubin (TB) levels and arterial stiffness, measured by the brachial-ankle pulse wave velocity (baPWV), in patients with type 2 diabetes.

Methods

We conducted a cross-sectional analysis of 1,711 subjects with type 2 diabetes (807 men and 904 women; mean age, 57.1 years). The subjects were stratified based on gender-specific tertiles of TB values, and a high baPWV was defined as greater than 1,745 cm/s ( >75th percentile).

Results

The serum TB concentration was negatively correlated with the duration of diabetes, HbA1c, the 10-year Framingham risk score, and baPWV and was positively correlated with high-density lipoprotein cholesterol and the eGFR in both genders. Inverse association between TB categories and unadjusted prevalence of high PWV was only observed in women. After adjusting for confounding factors, the TB levels were inversely associated with a greater risk of a high baPWV, both as a continuous variable [a 1-SD difference; odds ratio (OR), 0.70; 95% confidence interval (CI), 0.54–0.90; P = 0.005] and when categorized in tertiles (the highest vs. the lowest tertile; OR, 0.49; 95% CI, 0.28–0.85; P = 0.011) in women but not in men. The relationship remained significant even after adjusting for retinopathy and nephropathy.

Conclusions

Low TB levels were significantly associated with arterial stiffness in Korean women with type 2 diabetes. Our data suggested that bilirubin may protect against macrovascular disease in diabetic women.     

The Age-Specific Quantitative Effects of Metabolic Risk Factors on Cardiovascular Diseases and Diabetes: A Pooled Analysis

Background

The effects of systolic blood pressure (SBP), serum total cholesterol (TC), fasting plasma glucose (FPG), and body mass index (BMI) on the risk of cardiovascular diseases (CVD) have been established in epidemiological studies, but consistent estimates of effect sizes by age and sex are not available.

Methods

We reviewed large cohort pooling projects, evaluating effects of baseline or usual exposure to metabolic risks on ischemic heart disease (IHD), hypertensive heart disease (HHD), stroke, diabetes, and, as relevant selected other CVDs, after adjusting for important confounders. We pooled all data to estimate relative risks (RRs) for each risk factor and examined effect modification by age or other factors, using random effects models.

Results

Across all risk factors, an average of 123 cohorts provided data on 1.4 million individuals and 52,000 CVD events. Each metabolic risk factor was robustly related to CVD. At the baseline age of 55–64 years, the RR for 10 mmHg higher SBP was largest for HHD (2.16; 95% CI 2.09–2.24), followed by effects on both stroke subtypes (1.66; 1.39–1.98 for hemorrhagic stroke and 1.63; 1.57–1.69 for ischemic stroke). In the same age group, RRs for 1 mmol/L higher TC were 1.44 (1.29–1.61) for IHD and 1.20 (1.15–1.25) for ischemic stroke. The RRs for 5 kg/m² higher BMI for ages 55–64 ranged from 2.32 (2.04–2.63) for diabetes, to 1.44 (1.40–1.48) for IHD. For 1 mmol/L higher FPG, RRs in this age group were 1.18 (1.08–1.29) for IHD and 1.14 (1.01–1.29) for total stroke. For all risk factors, proportional effects declined with age, were generally consistent by sex, and differed by region in only a few age groups for certain risk factor-disease pairs.

Conclusion

Our results provide robust, comparable and precise estimates of the effects of major metabolic risk factors on CVD and diabetes by age group.     

Obesity Indexes and Total Mortality among Elderly Subjects at High Cardiovascular Risk: The PREDIMED Study

Background

Different indexes of regional adiposity have been proposed for identifying persons at higher risk of death. Studies specifically assessing these indexes in large cohorts are scarce. It would also be interesting to know whether a dietary intervention may counterbalance the adverse effects of adiposity on mortality.

Methods

We assessed the association of four different anthropometric indexes (waist-to-height ratio (WHtR), waist circumference (WC), body mass index (BMI) and height) with all-cause mortality in 7447 participants at high cardiovascular risk from the PREDIMED trial. Forty three percent of them were men (55 to 80 years) and 57% were women (60 to 80 years). All of them were initially free of cardiovascular disease. The recruitment took place in 11 recruiting centers between 2003 and 2009.

Results

After adjusting for age, sex, smoking, diabetes, hypertension, intervention group, family history of coronary heart disease, and leisure-time physical activity, WC and WHtR were found to be directly associated with a higher mortality after 4.8 years median follow-up. The multivariable-adjusted HRs for mortality of WHtR (cut-off points: 0.60, 0.65, 0.70) were 1.02 (0.78–1.34), 1.30 (0.97–1.75) and 1.55 (1.06–2.26). When we used WC (cut-off points: 100, 105 and 110 cm), the multivariable adjusted Hazard Ratios (HRs) for mortality were 1.18 (0.88–1.59), 1.02 (0.74–1.41) and 1.57 (1.19–2.08). In all analyses, BMI exhibited weaker associations with mortality than WC or WHtR. The direct association between WHtR and overall mortality was consistent within each of the three intervention arms of the trial.

Conclusions

Our study adds further support to a stronger association of abdominal obesity than BMI with total mortality among elderly subjects at high risk of cardiovascular disease. We did not find evidence to support that the PREDIMED intervention was able to counterbalance the harmful effects of increased adiposity on total mortality.

Trial Registration

Controlled-Trials.com ISRCTN35739639     

Parity and the Risk of Diabetes Mellitus among Chinese Women: A Cross-Sectional Evidence from the Tongji-Dongfeng Cohort Study

Objectives

Little is known about the long-term health impact of pregnancy on women. The objective of this study was to examine the association between parity and the risk of diabetes among a population of Chinese women.

Study design

A total of 14,196 women (aged ≥45 years) from the Dongfeng-Tongji Cohort study who had experienced at least one live birth completed baseline questionnaires, medical examinations, and provided baseline blood samples. Participants were categorized into four groups according to parity (one, two, three, or four or more live births). Logistic regression models were used to investigate the association between parity and the risk of diabetes after controlling potential confounders.

Results

The prevalence of diabetes in the study population was 18.0% (2,552/14,196). Fasting plasma glucose levels increased with the increasing number of live births (P<0.001) and parity had a positive graded association with diabetes without adjustment for any covariates (P for trend <0.001). After adjusting for potential confounders, women who had had two, three, and four or more live births had 1.35 times (95% CI, 1.20–1.52), 1.59 times (95% CI, 1.39–1.82) and 1.44 times (95% CI, 1.21–1.71), respectively, higher risk of diabetes compared with women who had had one live birth.

Conclusion

Multiparity was associated with increasing risk of diabetes in this population of Chinese women. These findings suggested that multiparity may be a risk factor for the development of diabetes among Chinese women. Future studies are needed to examine the physiological changes during pregnancy for risk of diabetes in later life.     

Diabetes Mellitus and Risk of Bladder Cancer: A Meta-Analysis of Cohort Studies

Objective

Diabetes is associated with increased risk of cancer at several sites, but its association with risk of bladder cancer is still controversial. We examined this association by conducting a systematic review and meta-analysis of cohort studies.

Methods

Studies were identified by searching PubMed, EMBASE, Scopus, Web of Science, Cochrane register, and Chinese National Knowledge Infrastructure (CNKI) databases through April 29, 2012. Summary relative risks (SRRs) with their corresponding 95% confidence intervals (CIs) were calculated using a random-effects model.

Results

A total of fifteen cohort studies were included in this meta-analysis. Analysis of all studies showed that diabetes was associated with a borderline statistically significant increased risk of bladder cancer (RR 1.11, 95% CI 1.00–1.23; p<0.001 for heterogeneity; I² = 84%). When restricting the analysis to studies that had adjusted for cigarette smoking (n = 6) or more than three confounders (n = 7), the RRs were 1.32 (95% CI 1.18–1.49) and 1.20 (95% CI 1.02–1.42), respectively. There was no significant publication bias (p = 0.62 for Egger’s regression asymmetry test).

Conclusions

Our findings support that diabetes was associated with an increased risk of bladder cancer. More future studies are warranted to get a better understanding of the association and to provide convincing evidence for clinical practice in bladder cancer prevention.     

A Meta-Analysis of Parental Smoking and the Risk of Childhood Brain Tumors

Objective

Previous studies regarding the association between parental smoking and the risk of childhood brain tumors (CBT) have reported inconsistent results. We performed a meta-analysis to summarize evidence on this association and to quantify the potential dose-response relationship.

Methods

A systematic literature search was conducted in the Medline and Embase databases. The summary relative risks (RRs) with 95% confidence intervals (CIs) were calculated. Dose–response meta-analysis was also performed for studies that reported categorical risk estimates for a series of smoking exposure levels.

Results

A total of 17 studies fulfilled the inclusion criteria. In the meta-analyses, the summary RRs (95% CIs) of CBT for maternal smoking during pregnancy, paternal smoking during pregnancy, maternal smoking before pregnancy, and paternal smoking before pregnancy were 0.96 (0.86–1.07), 1.09 (0.97–1.22), 0.93 (0.85–1.00), and 1.09 (1.00–1.20), respectively. Dose-response meta-analysis also showed no significant association between parental smoking and the risk of CBT.

Conclusions

Findings from our meta-analysis indicate that parental smoking may not be associated with a risk of CBT.     

Ratio of Trunk to Leg Volume as a New Body Shape Metric for Diabetes and Mortality

Background

Body shape is a known risk factor for diabetes and mortality, but the methods estimating body shape, BMI and waist circumference are crude. We determined whether a novel body shape measure, trunk to leg volume ratio, was independently associated with diabetes and mortality.

Methods

Data from the National Health and Nutritional Examination Survey 1999–2004, a study representative of the US population, were used to generate dual-energy X-ray absorptiometry-derived trunk to leg volume ratio and determine its associations to diabetes, metabolic covariates, and mortality by BMI category, gender, and race/ethnicity group.

Results

The prevalence of pre-diabetes and diabetes increased with age, BMI, triglycerides, blood pressure, and decreased HDL level. After adjusting for covariates, the corresponding fourth to first quartile trunk to leg volume ratio odds ratios (OR) were 6.8 (95% confidence interval [CI], 4.9–9.6) for diabetes, 3.9 (95% CI, 3.0–5.2) for high triglycerides, 1.8 (95% CI, 1.6–2.1) for high blood pressure, 3.0 (95% CI, 2.4–3.8) for low HDL, 3.6 (95% CI, 2.8–4.7) for metabolic syndrome, and 1.76 (95% CI, 1.20–2.60) for mortality. Additionally, trunk to leg volume ratio was the strongest independent measure associated with diabetes (P<0.001), even after adjusting for BMI and waist circumference. Even among those with normal BMI, those in the highest quartile of trunk to leg volume ratio had a higher likelihood of death (5.5%) than those in the lowest quartile (0.2%). Overall, trunk to leg volume ratio is driven by competing mechanisms of changing adiposity and lean mass.

Conclusions

A high ratio of trunk to leg volume showed a strong association to diabetes and mortality that was independent of total and regional fat distributions. This novel body shape measure provides additional information regarding central adiposity and appendicular wasting to better stratify individuals at risk for diabetes and mortality, even among those with normal BMI.