Prospective associations of hemoglobin A1c and c-peptide with risk of diabetes-related cancers in the Cancer Prevention Study-II Nutrition Cohort

Increased colorectal cancer risk in prediabetes: A meta-analysis

BACKGROUND

Previous research yielded conflicting results regarding the association between prediabetes and colorectal cancer (CRC).

AIM

To systematically assess the incidence of CRC in individuals with prediabetes compared with individuals with normoglycemia via a meta-analysis.

METHODS

Relevant cohort studies were acquired by searching MEDLINE, Web of Science, and EMBASE. A random-effects model was applied to combine the findings after accounting for heterogeneity. Several subgroup analyses were conducted to assess the impact of study characteristics on the results.

RESULTS

Eleven cohort studies involving 4996352 participants, including 383917 (7.7%) with prediabetes at baseline, were analyzed in this meta-analysis. Over a mean follow-up period of 6.5 years, the combined findings revealed that individuals with prediabetes at baseline had a higher likelihood of developing CRC than those with normoglycemia [risk ratio (RR) = 1.18, 95% confidence interval = 1.11 to 1.25, P < 0.001] with low statistical heterogeneity (I² = 27%). Subgroup analyses indicated that the association between prediabetes and an increased risk of CRC was mainly observed in studies defining prediabetes using impaired fasting glucose (RR = 1.24) and slightly elevated hemoglobin A1c levels (RR = 1.18) but not in those that defined prediabetes using impaired glucose tolerance (RR = 1.06). Other study characteristics such as design, country, participant age and sex, the duration of follow-up, or adjustment for body mass index did not significantly impact the results (all P > 0.05).

CONCLUSION

People with prediabetes might have a higher likelihood of developing CRC than individuals with normoglycemia.

Glycemic control and cancer outcomes in oncologic patients with diabetes: an Italian Association of Medical Oncology (AIOM), Italian Association of Medical Diabetologists (AMD), Italian Society of Diabetology (SID), Italian Society of Endocrinology (SIE), Italian Society of Pharmacology (SIF) multidisciplinary critical view

BACKGROUND

 Increasing evidence suggests that diabetes increases the risk of developing different types of cancer. Hyperinsulinemia, hyperglycemia and chronic inflammation, characteristic of diabetes, could represent possible mechanisms involved in cancer development in diabetic patients. At the same time, cancer increases the risk of developing new-onset diabetes, mainly caused by the use of specific anticancer therapies. Of note, diabetes has been associated with a ∼10% increase in mortality for all cancers in comparison with subjects who did not have diabetes. Diabetes is associated with a worse prognosis in patients with cancer, and more recent findings suggest a key role for poor glycemic control in this regard. Nevertheless, the association between glycemic control and cancer outcomes in oncologic patients with diabetes remains unsettled and poorly debated.

PURPOSE

 The current review seeks to summarize the available evidence on the effect of glycemic control on cancer outcomes, as well as on the possibility that timely treatment of hyperglycemia and improved glycemic control in patients with cancer and diabetes may favorably affect cancer outcomes.

Prospective Analysis of Circulating Biomarkers and Ovarian Cancer Risk in the UK Biobank

BACKGROUND

Risk factors have a limited ability to predict individuals at high risk of developing ovarian cancer among average-risk women, highlighting the need for discovery of novel biomarkers. In the UK Biobank, we investigated serum biomarkers commonly measured in clinical laboratory tests and ovarian cancer risk.

METHODS

We conducted a prospective analysis of 20 serum biomarkers and ovarian cancer risk in 232,037 female UK Biobank participants (including 1,122 incident ovarian cancer cases diagnosed from 2006 to 2020). Multivariable adjusted Cox proportional hazards models were used to examine associations between biomarkers and ovarian cancer risk overall and by histotype. FDR was used to account for multiple testing.

RESULTS

Overall, higher levels of insulin-like growth factor (IGF)-1 [RRquartile 4 vs. 1 = 0.73; 95% confidence interval (CI), 0.60-0.87; P-trend = 0.002/FDR = 0.04], HbA1c (RRquartile 4 vs. 1 = 0.74; 95% CI, 0.62-0.89; P-trend = 0.002/FDR = 0.04), and alanine aminotransferase (RRquartile 4 vs. 1 = 0.76; 95% CI, 0.63-0.91; P-trend = 0.002/FDR = 0.04) were significantly associated with lower ovarian cancer risk. When stratified by histotype, higher IGF1 levels were associated with lower risk of serous (RRquartile 4 vs. 1 = 0.73; 95% CI, 0.58-0.91; P-trend = 0.01/FDR = 0.20) and clear cell tumors (RRquartile 4 vs. 1 = 0.18; 95% CI, 0.07-0.49; P-trend = 0.001/FDR = 0.02), and higher HbA1c levels were associated with lower risk of serous tumors (RRquartile 4 vs. 1 = 0.73; 95% CI, 0.59-0.90; P-trend = 0.004/FDR = 0.08).

CONCLUSIONS

We observed that higher levels of circulating IGF1, HbA1c, and alanine aminotransferase were associated with lower ovarian cancer risk.

IMPACT

These results suggest metabolism of glucose/amino acid and insulin/IGF1 signaling pathway may be contributing to ovarian carcinogenesis. Further research is needed to replicate our findings and elucidate how systemic changes in metabolism impact ovarian carcinogenesis.

Optimal glycaemic control and the reduced risk of colorectal adenoma and cancer in patients with diabetes: a population-based cohort study

OBJECTIVE

Whether varying degrees of glycaemic control impact colonic neoplasm risk in patients with diabetes mellitus (DM) remains uncertain.

DESIGN

Patients with newly diagnosed DM were retrieved from 2005 to 2013. Optimal glycaemic control at baseline was defined as mean haemoglobin A1c (HbA1c)<7%. Outcomes of interest included colorectal cancer (CRC) and colonic adenoma development. We used propensity score (PS) matching with competing risk models to estimate subdistribution HRs (SHRs). We further analysed the combined effect of baseline and postbaseline glycaemic control based on time-weighted mean HbA1c during follow-up.

RESULTS

Of 88 468 PS-matched patients with DM (mean (SD) age: 61.5 (±11.7) years; male: 47 127 (53.3%)), 1229 (1.4%) patients developed CRC during a median follow-up of 7.2 (IQR: 5.5-9.4) years. Optimal glycaemic control was associated with lower CRC risk (SHR 0.72; 95% CI 0.65 to 0.81). The beneficial effect was limited to left-sided colon (SHR 0.71; 95% CI 0.59 to 0.85) and rectum (SHR 0.71; 95% CI 0.57 to 0.89), but not right-sided colon (SHR 0.86; 95% CI 0.67 to 1.10). Setting suboptimal glycaemic control at baseline/postbaseline as a reference, a decreased CRC risk was found in optimal control at postbaseline (SHR 0.79), baseline (SHR 0.71) and both time periods (SHR 0.61). Similar associations were demonstrated using glycaemic control as a time-varying covariate (HR 0.75). A stepwise greater risk of CRC was found (Ptrend<0.001) with increasing HbA1c (SHRs 1.34, 1.30, 1.44, 1.58 for HbA1c 7.0% to <7.5%, 7.5% to <8.0%, 8.0% to <8.5% and ≥8.5%, respectively). Optimal glycaemic control was associated with a lower risk of any, non-advanced and advanced colonic adenoma (SHRs 0.73-0.87).

CONCLUSION

Glycaemic control in patients with DM was independently associated with the risk of colonic adenoma and CRC development with a biological gradient.

Prediabetes and the risk of breast cancer: a meta-analysis

Background

Diabetes has been related to a higher risk of breast cancer (BC) in women. However, it remains unknown whether the incidence of BC is increased in women with prediabetes. A systematic review and meta-analysis was therefore performed to evaluate the relationship between prediabetes and risk of BC.

Methods

Observational studies with longitudinal follow-up relevant to the objective were found via searching Medline, Embase, Cochrane Library, and Web of Science. A fixed- or random-effects model was used to pool the results depending on heterogeneity.

Results

Eight prospective cohort studies and two nest case-control studies were included. A total of 1069079 community women were involved, and 72136 (6.7%) of them had prediabetes at baseline. During a mean duration follow-up of 9.6 years, 9960 (0.93%) patients were diagnosed as BC. Pooled results with a fixed-effects model showed that women with prediabetes were not associated with a higher incidence of BC as compared to those with normoglycemia (risk ratio: 0.99, 95% confidence interval: 0.93 to 1.05, p = 0.72) with mild heterogeneity (p for Cochrane Q test = 0.42, I2 = 3%). Subgroup analyses showed that study characteristics such as study design, menopausal status of the women, follow-up duration, diagnostic criteria for prediabetes, methods for validation of BC cases, and study quality scores did not significantly affect the results (p for subgroup analyses all > 0.05).

Conclusion

Women with prediabetes may not be associated with an increased risk of BC as compared to women with normoglycemia.

Time trajectories of key cardiometabolic parameters and of cardiovascular risk in subjects with diabetes in a real world setting

BACKGROUND AND AIMS

Diabetes is associated with increased cardiovascular risk. Glycated haemoglobin (HbA_1c), lipid parameters and blood pressure are known risk factors for adverse outcome. The aim of the study was to explore the time trajectories of these key parameters and of the associated cardiovascular risk.

METHODS

We linked the diabetes electronic health records to the laboratory information system so as to investigate the trajectories of key metabolic parameters from 3 years prior to the diagnosis of diabetes to 10 years after diagnosis. We calculated the cardiovascular risk at the different time points during this period using the United Kingdom Prospective Study (UKPDS) risk engine.

RESULTS

The study included 21,288 patients. The median age at diagnosis was 56 years and 55.3% were male. There was a sharp decrease in HbA_1c after diagnosis of diabetes, but there was a progressive rise thereafter. All lipid parameters after diagnosis also improved in the year of diagnosis, and these improvements persisted even up to 10 years post-diagnosis. There was no discernible trend in mean systolic or diastolic blood pressures following diagnosis of diabetes. There was a slight decrease in the UKPDS-estimated cardiovascular risk after diagnosis of diabetes followed by a progressive increase. Estimated glomerular filtration rate declined at an average rate of 1.33 ml/min/1.73 m²/year.

CONCLUSIONS

Our data suggest that lipid control should be tightened with increasing duration of diabetes since this is more readily achievable than HbA_1c lowering and since other factors such as age and duration of diabetes are unmodifiable.