@article {1240, title = {Differential white blood cell count and type 2 diabetes: systematic review and meta-analysis of cross-sectional and prospective studies.}, journal = {PLoS One}, volume = {5}, year = {2010}, month = {2010 Oct 18}, pages = {e13405}, abstract = {

OBJECTIVE: Biological evidence suggests that inflammation might induce type 2 diabetes (T2D), and epidemiological studies have shown an association between higher white blood cell count (WBC) and T2D. However, the association has not been systematically investigated.

RESEARCH DESIGN AND METHODS: Studies were identified through computer-based and manual searches. Previously unreported studies were sought through correspondence. 20 studies were identified (8,647 T2D cases and 85,040 non-cases). Estimates of the association of WBC with T2D were combined using random effects meta-analysis; sources of heterogeneity as well as presence of publication bias were explored.

RESULTS: The combined relative risk (RR) comparing the top to bottom tertile of the WBC count was 1.61 (95\% CI: 1.45; 1.79, p = 1.5*10(-18)). Substantial heterogeneity was present (I(2) = 83\%). For granulocytes the RR was 1.38 (95\% CI: 1.17; 1.64, p = 1.5*10(-4)), for lymphocytes 1.26 (95\% CI: 1.02; 1.56, p = 0.029), and for monocytes 0.93 (95\% CI: 0.68; 1.28, p = 0.67) comparing top to bottom tertile. In cross-sectional studies, RR was 1.74 (95\% CI: 1.49; 2.02, p = 7.7*10(-13)), while in cohort studies it was 1.48 (95\% CI: 1.22; 1.79, p = 7.7*10(-5)). We assessed the impact of confounding in EPIC-Norfolk study and found that the age and sex adjusted HR of 2.19 (95\% CI: 1.74; 2.75) was attenuated to 1.82 (95\% CI: 1.45; 2.29) after further accounting for smoking, T2D family history, physical activity, education, BMI and waist circumference.

CONCLUSIONS: A raised WBC is associated with higher risk of T2D. The presence of publication bias and failure to control for all potential confounders in all studies means the observed association is likely an overestimate.

}, keywords = {Adult, Aged, Cross-Sectional Studies, Diabetes Mellitus, Type 2, Female, Humans, Leukocyte Count, Male, Middle Aged, Prospective Studies}, issn = {1932-6203}, doi = {10.1371/journal.pone.0013405}, author = {Gkrania-Klotsas, Effrossyni and Ye, Zheng and Cooper, Andrew J and Sharp, Stephen J and Luben, Robert and Biggs, Mary L and Chen, Liang-Kung and Gokulakrishnan, Kuppan and Hanefeld, Markolf and Ingelsson, Erik and Lai, Wen-An and Lin, Shih-Yi and Lind, Lars and Lohsoonthorn, Vitool and Mohan, Viswanathan and Muscari, Antonio and Nilsson, Goran and Ohrvik, John and Chao Qiang, Jiang and Jenny, Nancy Swords and Tamakoshi, Koji and Temelkova-Kurktschiev, Theodora and Wang, Ya-Yu and Yajnik, Chittaranjan Sakerlal and Zoli, Marco and Khaw, Kay-Tee and Forouhi, Nita G and Wareham, Nicholas J and Langenberg, Claudia} } @article {1354, title = {Markers of inflammation in prevalent and incident Parkinson{\textquoteright}s disease in the Cardiovascular Health Study.}, journal = {Parkinsonism Relat Disord}, volume = {18}, year = {2012}, month = {2012 Mar}, pages = {274-8}, abstract = {

BACKGROUND: Studies demonstrate existence of inflammation in prevalent Parkinson{\textquoteright}s disease (PD). We assessed associations of baseline levels of inflammatory markers with prevalent PD at baseline (1989) and incident PD identified over 13 years of follow-up of the Cardiovascular Health Study.

METHODS: Blood samples at baseline were measured for fibrinogen, interleukin-6, tumor necrosis factor-α, C-reactive protein, albumin, and white blood cells. The analysis included 60 prevalent and 154 incident PD cases.

RESULTS: Risk of prevalent PD was significantly higher per doubling of IL-6 among women (odds ratio [OR]=1.5, 95\% confidence interval [CI]: 1.0, 2.4) and WBC among men (OR: 2.4, 95\% CI: 1.2, 4.9) in multivariate models. Risk of incident PD was not associated with higher levels of any biomarker after adjusting for age, smoking, African American race, and history of diabetes. Inverse associations with incident PD were observed per doubling of C-reactive protein (OR=0.9; 95\% CI: 0.8, 1.0) and of fibrinogen among women (OR=0.4; 95\% CI: 0.2, 0.8).

CONCLUSIONS: Although inflammation exists in PD, it may not represent an etiologic factor. Our findings suggest the need for larger studies that measure inflammatory markers before PD onset.

}, keywords = {Aged, Aged, 80 and over, Albumins, Biomarkers, C-Reactive Protein, Enzyme-Linked Immunosorbent Assay, Female, Fibrinogen, Humans, Incidence, Inflammation, Interleukin-6, Leukocyte Count, Male, Parkinson Disease, Prevalence, Risk Factors, Tumor Necrosis Factor-alpha}, issn = {1873-5126}, doi = {10.1016/j.parkreldis.2011.11.003}, author = {Ton, Thanh G N and Jain, Samay and Biggs, Mary L and Thacker, Evan L and Strotmeyer, Elsa S and Boudreau, Robert and Newman, Anne B and Longstreth, W T and Checkoway, Harvey} }