What is the relationship between passive smoking and type 2 diabetes mellitus [T2DM]?

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Introduction

Present existing body of knowledge or existing problem
State “gaps” in knowledge/understanding
What “gaps” will your study address?
EXAMPLE:
The prevalence of diabetes is increasing rapidly worldwide, and it is estimated that 439 million adults will be affected by diabetes by 2030
Type 2 diabetes(T2DM)
identification of risk factors of T2DM is of significant importance to the primary prevention
40% of children, 33% of male nonsmokers and 35% of female non-smokers were exposed to passive smoking worldwide
Passive smoking can cause disease, disability, and death
Little is known about the relationship between passive smoking and T2DM risk.
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Research Question

What is the relationship between passive smoking and type 2 diabetes mellitus [T2DM]?

THIS IS JUST A SAMPLE HOW THE POWER will look like— pls use this as sampls to the topic

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Objectives (or Specific Aims)

Meta-analysis to systematically assess the association between passive smoking and risk of T2DM based on prospective cohort studies.
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Methods

Eligibility criteria:

Types of studies
Types of participants
Types of interventions

Types of outcome measures
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Methods (Cont.)

Search Strategies and Data Sources
Systematic search of PubMed, EMBASE, the Cochrane library and Web of Science
Date: 2000 to 2013 to identify relevant prospective cohort studies regarding the association between passive smoking and risk of T2DM.
Searched the reference lists of all retrieved articles to identify any additional literatures.
English language
The search terms were:
Diabetes mellitus, type 2 OR Diabetes mellitus OR Pre-diabetic state OR impaired fasting glucose OR impaired glucose tolerance OR Metabolic syndrome OR Glucose intolerance OR Hyperglycemia OR Glucose metabolism disorders OR Insulin resistance OR Glucose) AND (Tobacco smoke pollution OR Passive smoking OR Air pollution, tobacco smoke OR Second-hand smoking OR Involuntary smoking)
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Methods (Cont.)

Methodological Quality Assessment
Two independent reviewers; disagreements would be resolved by consensus
The reference groups were never smokers who were not exposed to passive smoking
Risk estimates (including RRs, ORs and HRs) adjusted for the maximum number of confounding variables with corresponding 95%Cis
Data extraction
Variable extracted:
Name of the first author, publication year, study location, age of the participants, total number of participants involved, confounding factors that were adjusted for in the analysis
A 9-star system based on the Newcastle-Ottawa Scale (NOS) was used for quality assessment.
4, 2, 3 scores were assigned for selection of study groups, comparability of study groups, assessment of outcomes and adequacy of follow-up.
Studies with scores of 0–3, 4–6, 7–9 were considered as low, moderate and high quality, respectively
Data Synthesis
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Results

Figure 1. Flow chart of the selection of publications included in

the meta-analysis.

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Results (Cont.)

Description of the selected studies and methodological quality
Characteristics of the studies:
Studies were conducted in United States, Japan, Germany and South Korea, respectively.
The population size per study ranged from 885 to 100,526, with a total of 112,351 participants.
Three studies consisted of males and females and one study involved only females.
Adjusted RRs (ORs/HRs) were reported in all studies.
Adjustment for potential confounding factors differed across studies
Main adjusted factors were: age, sex, body mass index (BMI), alcohol drinking, family or parental history of diabetes, physical activity and hypertension.
The maximum follow-up years were 4, 6, 7 and 24 years.
Quality assessment of NOS: 1 study [high quality; 3 moderate quality]
Discussion

Present findings in relation to “big picture”
Compare/contrast to other related studies
May include:
Implications
Limitations
Future directions
Example:
Results suggested that passive smoking was associated with a significantly increased risk of T2DM [28% increase in RR of T2DM]
A recent meta-analysis [25 cohort studies]: active smoking was associated with a 44% increase in RR (RR = 1.44, 95%CI: 1.31–1.58) of T2DM
Similar results were found in the study by Zhang L et al. [passive smoking was associated with 10% increase in RR]
Explanation: dilution of passive smoke by room air, which makes a non-smoker be exposed to less tobacco smoke than an active smoker.
Although passive smoking was associated with a smaller increase in RR of diabetes compared with active smoking, the burden of diabetes caused by the high prevalence of passive smoking in workplace and at home should not be neglected.
Possible mechanism
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Limitations

The results of this analysis were based on prospective cohort studies [observational studies cannot prove causality].
Although all the included studies controlled several known risk factors for T2DM, residual or unmeasured confounding may still affect the observed association.
Heterogeneity between studies in regard to adjusting for confounding factors, which may lead to misleading overall results.
Self-reported exposure status of passive smoking: possibility that participants tend to narrow their exposure status that may lead to underestimate or exaggerate of the risk estimates.
Small numbers of studies
Possibility of publication bias
No assessment of dose-response relationship between passive smoking and T2DM
Conclusions

The present study suggests that passive smoking is associated with an increased risk of T2DM.
Further well-designed studies are warranted to confirm this observed association.
The dose-response relationship should be well explored by studies in the future.
Implications

Importance of anti-smoking legislation to the reduction of T2DM risk by population level.
Achieve a significant reduction of T2DM in the burden to society, prohibitions on both passive and active smoking should be targeted.
Acknowledgement!

{Name the people that help in the process of your research study. Name the grant(s) that supported the study}
Thank you
You can add your information: name, email, phone number, and website

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