The question to be addressed by this review/meta-analysis is whether coronary artery calcium predicts cardiovascular event and/or all-cause mortality in patients with type 2 diabetes mellitus.

We selected relevant studies published between 1950, and September 4, 2012, from EMBASE, PubMed, Cochrane Library databases, Clinical Trials.gov, American Diabetes Association meetings (abstracts book) 2011 and 2012, European Association for the Study of Diabetes meetings (abstract book) 2011 and 2012.

We used the following combined text and Medical Subject Heading terms: coronary calcium and type 2 diabetes mellitus. The complete search used for Pubmed was(Calcium score [text] OR coronary artery calcification [text] OR coronary artery calcium [text]) AND ("Diabetes Mellitus"[Mesh] OR "Diabetes Mellitus, Type 2"[Mesh])

Only prospective observational studies will be included.

We will include studies that evaluated coronary artery calcium for the prediction of events in patients with type 2 diabetes

Studies will be consider eligible for inclusion if they were conducted in adults aged 18 years or older with type 2 diabetes, evaluated coronary artery calcium at baseline and evaluated the incidence of any events (cardiovascular events and/or all-cause mortality).

The exclusion criteria are as follow:

(i) cross-sectional or retrospective studies;

(ii) duplicate publications or substudies of included studies;

(iii) studies that lack data for analysis.

We will consider the presence of any coronary artery calcification as the exposure.

The control group (non-exposed group) will be the group without any coronary artery calcium.

Primary outcomes

Any cardiovascular event and/or all-cause mortality.

Secondary outcomes

None

Risk of bias will be evaluated according to New-Castle-Ottawa quality assessment scale for cohort studies. Study quality assessment will include selection criteria, comparability and outcome assessment.

An overall relative risk (RR) will be calculated to assess the predictive value of coronary artery calcium for all-cause mortality and/or CV events. We will use the Cochrane Q test to evaluate heterogeneity between studies and consider a threshold P value less than 0.1 as statistically significant. We will also use the I-squared testing to evaluate the magnitude of the heterogeneity between studies. We will calculate the pooled estimates of the mean differences in outcomes before and after the intervention by using a random-effects model (DerSimonian–Laird method) to adequately account for the additional uncertainty associated with study–study variability in the effect of the intervention.

Receiver operating characteristic (ROC) curves were constructed to obtain the pooled estimates of sensitivity and specificity of coronary artery calcium for the development of outcomes. The average likelihood ratio of the positive and negative test result will be calculated.

Exploration of subgroups will be based on meta-regression models.

Caroline Kaercher Kramer

Leadership Sinai Centre for Diabetes

Mount Sinai Hospital

60 Murray Street, Suite L5-025, Mailbox 21

Toronto, ON

Canada M5T3L9

carolinekkramer@gmail.com

None

Dr Caroline Kramer, Leadership Sinai Centre for Diabetes
Dr Ravi Retnakaran, Leadership Sinai Centre for Diabetes
Dr Bernard Zinman, Leadership Sinai Centre for Diabetes
Dr Luis Canani, Hospital de Clinicas de Porto Alegre/Brazil
Dr Jorge Gross, Hospital de Clinicas de Porto Alegre/Brazil
Dr Ticiana Rodrigues, Hospital de Clinicas de Porto Alegre/Brazil

01 September 2012

31 October 2012

C.K.K holds a Canadian Diabetes Association (CDA) Postdoctoral Fellowship Award. R. R. holds an Ontario Ministry of Research and Innovation Early Researcher Award. B. Z. holds the Sam and Judy Pencer Family Chair in Diabetes Research at Mount Sinai Hospital and University of Toronto.

None known

English

Canada

Subject indexing assigned by CRD

Calcinosis; Cardiovascular Diseases; Coronary Vessels; Diabetes Mellitus, Type 2; Humans; Risk Assessment; Risk Factors

07 September 2012

07 September 2012