Obesity and C-reactive protein in various populations: a systematic review and meta-analysis

Obesity has been associated with elevated levels of C-reactive protein (CRP), a marker of inflammation and predictor of cardiovascular risk. The objective of this systematic review and meta-analysis was to estimate the associations between obesity and CRP according to sex, ethnicity and age. MEDLINE and EMBASE databases were searched through October 2011. Data from 51 cross-sectional studies that used body mass index (BMI), waist circumference (WC) or waist-to-hip ratio (WHR) as measure of obesity were independently extracted by two reviewers and aggregated using random-effects models. The Pearson correlation (r) for BMI and ln(CRP) was 0.36 (95% confidence interval [CI], 0.30-0.42) in adults and 0.37 (CI, 0.31-0.43) in children. In adults, r for BMI and ln(CRP) was greater in women than men by 0.24 (CI, 0.09-0.37), and greater in North Americans/Europeans than Asians by 0.15 (CI, 0-0.28), on average. In North American/European children, the sex difference in r for BMI and ln(CRP) was 0.01 (CI, -0.08 to 0.06). Although limited to anthropometric measures, we found similar results when WC and WHR were used in the analyses. Obesity is associated with elevated levels of CRP and the association is stronger in women and North Americans/Europeans. The sex difference only emerges in adulthood.

Prevalence of cerebral palsy in Quebec: alternative approaches

AIM

To provide an estimate of the period prevalence of cerebral palsy (CP) in the province of Quebec.

METHODS

Children with CP were identified from three consecutive birth cohorts (1999-2001) from the Quebec CP Registry, covering 6 of the 17 administrative health regions of the province. Two inferential approaches were applied for period prevalence estimation, frequentist and bayesian.

RESULTS

228 children were identified with CP. Using a frequentist approach, the overall prevalence of CP was 1.84 per 1,000 children aged 9-11 years living in those areas in 2010 (95% CI 1.60-2.08). Using a bayesian approach taking into account the uncertainty about the registry's sensitivity in capturing all cases, the overall prevalence is higher at 2.30 per 1,000 children with a 95% CI (1.99-2.65).

CONCLUSION

Using a bayesian approach to adjust for the registry's known high specificity and lower sensitivity, the prevalence estimate is in concordance with worldwide estimates and estimates using administrative databases in western Canadian provinces. Future studies are needed to validate the diagnosis of CP within administrative databases and to evaluate possible regional trends across Canada in both prevalence and health service utilization, which may highlight disparities in healthcare delivery.

Vitamin supplementation and blood pressure in Type 2 diabetes

AIMS

Vitamin D levels are inversely related to blood pressure. Given that low sun exposure can create a greater reliance on dietary sources of vitamin D, we aimed to determine whether dietary vitamin D and blood pressure associations differ between periods of low and high sun exposure.

METHODS

Dietary intake, vitamin supplementation, blood pressure, and anthropometric parameters were assessed each season for 1 year (174 adults with Type 2 diabetes). Separate linear regression models were constructed for high and low sun exposure periods to examine associations of systolic blood pressure with dietary vitamin D intake and vitamin supplement use (adjusted for age, gender, BMI, ethnicity, smoking, alcohol, physical activity, antihypertensive medication and nutrient intake). Robustness of findings was confirmed with within-subject repeated measures analysis, including an interaction term for sun exposure period.

RESULTS

Vitamin D intake from food sources was low year-round and no conclusive association with blood pressure was identified during either period. Systolic blood pressure was 5.1 mmHg lower during the low sun exposure period (95% CI 0.5-9.7) in daily supplement users compared with non-users. The interaction term between supplement use and sun exposure period was significant (low sun exposure* no supplement, P = 0.02). Systolic blood pressure was relatively stable in users (low and high sun exposure periods, respectively, mean ± SE: 135.2 ± 2.6 mmHg and 134.2 ± 2.5 mmHg), but not in non-users (140.2 ± 2.7 mmHg and 130.5 ± 2.5 mmHg).

CONCLUSIONS

Vitamin supplementation may stabilize systolic blood pressure in adults with Type 2 diabetes across seasons.

Mortality in diabetes compared with previous cardiovascular disease: a gender-specific meta-analysis

AIMS

Diabetes has been described as a cardiovascular disease (CVD) risk equivalent. There is evidence, however, that its impact may differ between women and men. For this reason, our study aimed to obtain gender-specific hazard ratios (HRs) comparing diabetes and CVD patients in terms of all-cause, CVD and coronary heart disease (CHD) mortality.

METHODS

Individuals with diabetes (without CVD) and those with CVD (without diabetes) were examined through a systematic review of articles that provided gender-specific HRs for mortality. Searches included Medline, Embase and the Cochrane Library database (from January 1998 to December 2009) and exploded MeSH headings [cardiovascular diseases, risk, epidemiologic studies, case-control studies, cohort studies, mortality, outcome assessment (health care), sex factors, survival analysis and diabetes mellitus, type 2]. Two observers selected and reviewed the studies and hierarchical Bayesian random-effects models were used to combine HRs, thereby accommodating any between-study differences through inclusion of a between-study variance in HRs.

RESULTS

Out of 5425 studies, nine were relevant (0.17%). CVD and CHD mortality in men was lower for diabetes alone (CVD mortality HR: 0.82, 95% CrI: 0.69-0.98; CHD mortality HR: 0.73, 95% CrI: 0.65-0.83). In contrast, rates appeared to be higher in women with diabetes alone (CVD mortality HR: 1.29, 95% CrI: 0.79-2.26; CHD mortality HR: 1.28, 95% CrI: 0.75-2.22), although wide credible intervals precluded any definitive conclusions. All-cause mortality in men was similar for diabetes and previous CVD (HR: 1.02, 95% CrI: 0.93-1.12) whereas, among women, it was at least as high and possibly higher for diabetes alone (HR: 1.25, 95% CrI: 0.89-1.76).

CONCLUSION

Compared with previous CVD, diabetes alone leads to lower CVD and CHD mortality risk in men, and similar all-cause mortality. In contrast, although further studies are needed, it is possible that diabetes leads to higher CVD, CHD and all-cause mortality in women.

Abdominal adiposity and daily step counts as determinants of glycemic control in a cohort of patients with type 2 diabetes mellitus

Objective:

Favorable effects of walking levels on glycemic control have been hypothesized to be mediated through reductions in abdominal adiposity, but this has not been well studied. We addressed this issue in patients treated for type 2 diabetes.

Design:

Cross-sectional analysis.

Subjects:

A total of 201 subjects with type 2 diabetes underwent assessments of pedometer-measured daily step counts, blood pressure, A1C and anthropometric measures (2006–2010). Associations of anthropometric indicators of abdominal adiposity (that is, waist circumference; waist-to-hip ratio (WHR)) with A1C were evaluated through linear regression models adjusting for age, ethnicity, sex and the use of insulin and oral hypoglycemic agents. Models including waist circumference were additionally adjusted for body mass index (BMI). A similar approach was used to examine A1C and daily step associations.

Results:

Among the 190 subjects (mean age 60 years; mean BMI 30.4 kg m⁻²), mean values (s.d.) for waist circumference and WHR were respectively, 99.1 cm (13.3) and 0.88 (0.07) in women, and 104.5 cm (13.1) and 0.97 (0.06) in men. Mean A1C and daily step count were respectively, 7.6% (1.4) and 5 338 steps per day (2609), and were similar for both sexes.

There was a 0.51% (95% confidence interval (CI): 0.10, 0.93) A1C increment per s.d. increase in waist circumference and a 0.32% (95% CI: 0.08, 0.56) A1C increment per s.d. increase in WHR in fully adjusted models. Each s.d. increase in daily step count was associated with clinically significant reductions in waist circumference and BMI. Each s.d. increase in daily steps was associated with a 0.21% (95% CI: 0.02, 0.41) A1C decrement that declined to 0.16% (95% CI: −0.35, 0.04) with further adjustment for anthropometric indicators of abdominal adiposity.

Conclusion:

Higher daily steps may be associated with lower A1C values both directly and via changes in abdominal adiposity.

Primary carnitine deficiency and sudden death: in vivo evidence of myocardial lipid peroxidation and sulfonylation of sarcoendoplasmic reticulum calcium ATPase 2

OBJECTIVES

Primary carnitine deficiency is an autosomal recessive disorder caused by mutations in the SLC22A5 gene which results in impaired carnitine transport, cytosolic fatty acid accumulation and impaired beta oxidation. The disease is associated with cardiomyopathy and arrhythmias, but the mechanism is unknown. We hypothesized that carnitine deficiency results in increased myocardial oxidative stress.

METHODS

We evaluated a 22-year-old woman with primary carnitine deficiency and ventricular fibrillation, as well as her first-degree relatives.

RESULTS

Sequencing of SLC22A5 identified two deleterious mutations (A142S and R488H) and a novel mutation predicted to be a splice variant. Histology demonstrated increased myocardial lipid deposition and swollen mitochondria. Immunohistochemistry demonstrated accumulation of the reactive aldehyde 4-hydroxy-2-nonenal, indicative of increased lipid peroxidation, and sulfonylation of sarcoendoplasmic reticulum calcium ATPase 2 at cysteine 674.

CONCLUSIONS

These findings suggest that increased oxidant stress may contribute to myocardial dysfunction and arrhythmogenesis in this disorder.

Association of the Charlson comorbidity index with mortality in systemic lupus erythematosus

OBJECTIVE

To investigate whether comorbidity as assessed by the Charlson Comorbidity Index (CCI) is associated with mortality in a long-term followup of systemic lupus erythematosus (SLE) patients.

METHODS

Data were collected from 499 SLE patients attending the Lupus Clinic at the McGill University Health Center, Montreal, Quebec, Canada, and 170 SLE patients from the Department of Rheumatology at Lund University Hospital, Lund, Sweden. This included data on comorbidity, demographics, disease activity, the Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index (SDI), and antiphospholipid antibody syndrome (APS). Variables were entered into a Cox proportional hazards survival model.

RESULTS

Mortality risk in the Montreal cohort was associated with the CCI (hazard ratio [HR] 1.57 per unit increase in the CCI, 95% confidence interval [95% CI] 1.18-2.09) and age (HR 1.04 per year increase in age, 95% CI 1.00-1.09). The CCI and age at diagnosis were also associated with mortality in the Lund cohort (CCI: HR 1.35, 95% CI 1.13-1.60; age: HR 1.09, 95% CI 1.05-1.12). Furthermore, the SDI was associated with mortality in the Lund cohort (HR 1.40, 95% CI 1.19-1.64), while a wide CI for the estimate in the Montreal cohort prevented a definitive conclusion (HR 1.20, 95% CI 0.97-1.48). We did not find a strong association between mortality and sex, race/ethnicity, disease activity, or APS in either cohort.

CONCLUSION

In this study, comorbidity as measured by the CCI was associated with decreased survival independent of age, lupus disease activity, and damage. This suggests that the CCI may be useful in capturing comorbidity for clinical research in SLE.

Features associated with cardiac abnormalities in systemic lupus erythematosus

OBJECTIVES

To determine the prevalence of echocardiographic abnormalities and identify associated clinical and laboratory features in a large systemic lupus erythematosus (SLE) cohort.

METHODS

Patients fulfilling ACR criteria for SLE underwent a transthoracic echocardiogram (TTE) between January 2005 and June 2006. Variables used as potential correlates included age, sex, ethnicity, lupus duration, lupus disease activity (SLEDAI), cumulative damage (SLICC/ACR damage index (DI)), arterial hypertension, diabetes, current smoking, medication use and laboratory data. Multivariate logistic regression was used to examine the association between TTE abnormalities and potential determinants.

RESULTS

For the 217 subjects with a TTE performed during the study, the main abnormalities were of the mitral valve (37.3%) and included thickening (25.4%) and insufficiency (25.8%). Other findings included pulmonary artery pressure (PAP)  ≥  30( )mm( )Hg (10.1%), pericardial effusion (4.6%), hypokinesis (2.8%), and aortic insufficiency (3.7%). In multivariate analysis, mitral insufficiency was associated with the use of corticosteroids (OR 2.90; 95%CI 1.42-5.94) and hypokinesis with angiotensin-converting enzyme inhibitors (12.89; 1.06-157.18). Elevated PAP was associated with age (1.04; 1.01-1.07) and with DI (1.20; 1.01-1.42).

CONCLUSION

Valvular abnormalities are frequent in patients with SLE, with mitral valve lesions occurring in over one third. TTE screening may be indicated in patients with SLE, especially for those with identified risk factors such as corticosteroid use.