SynthesisDiabetologia2014
HbA1c, fasting and 2 h plasma glucose in current, ex- and never-smokers: a meta-analysis.
Synthesis in Diabetologia, 2014. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 29 papers, 3 of them syntheses that pooled it.
What it found
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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
29 citing papers in PubMed, 3 syntheses or guidelines pooled it, 53 citations in OpenAlex.
- Health risk behaviours, mental health and HbA1c: an overview of reviews of observational studies.BMJ open · 2025Pooled it
- Glycaemic control and its associated factors in patients with type 2 diabetes in the Middle East and North Africa: An updated systematic review and meta-analysis.Journal of advanced nursing · 2022Pooled it
- Pooled it
- Mediation of the association of smoking and microvascular complications by glycemic control in type 1 diabetes.PloS one · 2019Trial
- Trial
- Article
- Smoking cessation improves health status of patients with chronic diseases: evidence from a longitudinal study of older adults in China.BMC public health · 2025Article
- Metabolomic Insights into Smoking-Induced Metabolic Dysfunctions: A Comprehensive Analysis of Lipid and Amino Acid Metabolomes.Metabolites · 2025Article
- Hyperglycaemia in Pregnancy Is Less Frequent in Smokers: A French Observational Study of 15,801 Women.Journal of clinical medicine · 2024Article
- Ethnicity Affects A1C Levels in Patients With Diagnosed Type 2 Diabetes in Southern Israel.Diabetes spectrum : a publication of the American Diabetes Association · 2024Article
- Global variation in diabetes diagnosis and prevalence based on fasting glucose and hemoglobin A1c.Nature medicine · 2023Article
- Estimates of bladder cancer burden attributable to high fasting plasma glucose: Findings of the Global Burden of Disease Study 2019.Cancer medicine · 2023Article
- Association between smoking and glycemic control in men with newly diagnosed type 2 diabetes: a retrospective matched cohort study.Annals of medicine · 2022Article
- Interaction of diabetes and smoking on stroke: a population-based cross-sectional survey in China.BMJ open · 2018Article
- Association between White Blood Cell Counts within Normal Range and Hemoglobin A1c in a Korean Population.Endocrinology and metabolism (Seoul, Korea) · 2018Article
- Glucose patterns during an oral glucose tolerance test and associations with future diabetes, cardiovascular disease and all-cause mortality rate.Diabetologia · 2018Article
- Influence of cigarette smoking on hormone and lipid metabolism in women in late reproductive stage.Clinical interventions in aging · 2018Article
- Diabetic by HbA1c, Normal by OGTT: A Frequent Finding in the Mexico City Diabetes Study.Journal of the Endocrine Society · 2017Article
- Metrics for glycaemic control - from HbANature reviews. Endocrinology · 2017 · on this mapReview
- Response to Comment on Hofer et al. International Comparison of Smoking and Metabolic Control in Patients With Type 1 Diabetes. Diabetes Care 2016;39:e177-e178.Diabetes care · 2017Article
Corrections and comments
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Authors and funding
30 authors at 14 institutions in 12 countries.
Funding
Abstract
aims/hypothesisThe relationships between smoking and glycaemic variables have not been well explored. We compared HbA1c, fasting plasma glucose (FPG) and 2 h plasma glucose (2H-PG) in current, ex- and never-smokers.
methodsThis meta-analysis used individual data from 16,886 men and 18,539 women without known diabetes in 12 DETECT-2 consortium studies and in the French Data from an Epidemiological Study on the Insulin Resistance Syndrome (DESIR) and Telecom studies. Means of three glycaemic variables in current, ex- and never-smokers were modelled by linear regression, with study as a random factor. The I (2) statistic was used to evaluate heterogeneity among studies.
resultsHbA1c was 0.10% (95% CI 0.08, 0.12) (1.1 mmol/mol [0.9, 1.3]) higher in current smokers and 0.03% (0.01, 0.05) (0.3 mmol/mol [0.1, 0.5]) higher in ex-smokers, compared with never-smokers. For FPG, there was no significant difference between current and never-smokers (-0.004 mmol/l [-0.03, 0.02]) but FPG was higher in ex-smokers (0.12 mmol/l [0.09, 0.14]). In comparison with never-smokers, 2H-PG was lower (-0.44 mmol/l [-0.52, -0.37]) in current smokers, with no difference for ex-smokers (0.02 mmol/l [-0.06, 0.09]). There was a large and unexplained heterogeneity among studies, with I (2) always above 50%; I (2) was little changed after stratification by sex and adjustment for age and BMI. In this study population, current smokers had a prevalence of diabetes that was 1.30% higher as screened by HbA1c and 0.52% lower as screened by 2H-PG, in comparison with never-smokers. CONCLUSION/
interpretationAcross this heterogeneous group of studies, current smokers had a higher HbA1c and lower 2H-PG than never-smokers. This will affect the chances of smokers being diagnosed with diabetes.
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Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.