Additive interaction between the renin-angiotensin system and lipid metabolism for cancer in type 2 diabetes

Association of visceral adipose tissue with albuminuria and interaction between visceral adiposity and diabetes on albuminuria

AIMS

To explore the correlation between visceral adipose tissue and albuminuria, and whether there is interaction between visceral adipose tissue and diabetes on albuminuria.

METHODS

The study subjects were adult subjects (age ≥ 18 years) from the National Health and Nutrition Examination Surveys (NHANES) database of the USA in 2017-2018. Visceral fat area (VFA) was measured by dual-energy X-ray absorptiometry (DXA). Subjects were divided into three groups according to VFA: low (VFA 0-60cm2), medium (VFA 60-120 cm2) and high (VFA ≥ 120 cm2). Albuminuria was defined as urinary albumin-to-creatinine ratio (UACR) ≥ 30 mg/g. The statistical analysis software used is STATA 17.0.

RESULTS

Data pertaining to 2965 participants (2706 without albuminuria) were included in the analysis. High VFA is an independent risk factor for albuminuria (OR 1.367, 95% CI 1.023-1.827). In the low-VFA group, there is no significant association between diabetes and albuminuria (OR 1.415, 95% CI 0.145-13.849). In the medium-VFA group, diabetes is an independent risk factor for albuminuria (OR 2.217, 95% CI 1.095-4.488). In the high-VFA group, diabetes is also an independent risk factor for albuminuria (OR 5.150, 95% CI 3.150-8.421). There is an additive interaction between high VFA (VFA ≥ 120 cm2) and diabetes on the effect of albuminuria (RERI 3.757, 95% CI 0.927-6.587, p = 0.009), while no multiplication interaction (OR 1.881, 95% CI 0.997-1.023, p = 0.141).

CONCLUSIONS

High VFA may represent an independent risk factor for albuminuria. The amount of visceral fat may affect the effect of diabetes on albuminuria. The higher the visceral fat, the stronger the correlation between diabetes and albuminuria should be present. We suppose an additive interaction between VFA and diabetes on the effect of albuminuria.

Serum 25-hydroxyvitamin D concentrations and colorectal cancer incidence in adults with type 2 diabetes

BACKGROUND

To examine the association of serum 25-hydroxyvitamin D (25[OH]D) with colorectal cancer (CRC) risk in adults with type 2 diabetes (T2D).

METHODS

Using UK Biobank data, this study included 18,453 adults with T2D. Serum 25(OH)D concentrations were determined by the chemiluminescent immunoassay method. A Cox proportional hazards model was used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) for CRC outcomes.

RESULTS

During a median follow-up of 8.8 years, there were 284 incident CRC cases. Compared with adults with serum 25(OH)D concentrations <25.0 nmol/L, the adjusted HRs (95% CIs) for lower to higher serum 25(OH)D concentrations (25.0 to <50.0, 50.0 to <75.0, and ≥75.0 nmol/L) were 0.61 (0.46-0.82), 0.50 (0.34-0.74), and 0.53 (0.30-0.94), respectively (Ptrend = 0.001). The risk of CRC decreased by 19.0% for per 1-SD increment in serum 25(OH)D concentrations. A nonlinear association of serum 25(OH)D concentrations with CRC risk was observed using a restricted cubic spline analysis (P nonlinearity = 0.002).

CONCLUSIONS

Higher serum 25(OH)D concentrations were significantly and nonlinearly associated with a lower risk of CRC. These findings highlight the potential benefits of maintaining adequate vitamin D levels in CRC prevention among adults with T2D.

LACTB exerts tumor suppressor properties in epithelial ovarian cancer through regulation of Slug

Epithelial-mesenchymal transition (EMT) is a cellular mechanism used by cancer cells to acquire migratory and stemness properties. In this study, we show, through in vitro, in vivo, and 3D culture experiments, that the mitochondrial protein LACTB manifests tumor suppressor properties in ovarian cancer. We show that LACTB is significantly down-regulated in epithelial ovarian cancer cells and clinical tissues. Re-expression of LACTB negatively effects the growth of cancer cells but not of non-tumorigenic cells. Mechanistically, we show that LACTB leads to differentiation of ovarian cancer cells and loss of their stemness properties, which is achieved through the inhibition of the EMT program and the LACTB-dependent down-regulation of Snail2/Slug transcription factor. This study uncovers a novel role of LACTB in ovarian cancer and proposes new ways of counteracting the oncogenic EMT program in this model system.

Antidiabetic Medications and the Risk of Prostate Cancer in Patients with Diabetes Mellitus: A Systematic Review and Meta-analysis

BACKGROUND

Antidiabetic medications (ADMs) may modify prostate cancer (PCa) risk in patients with diabetes mellitus (DM). Accordingly, the current study assessed the possible associations between ADMs and the risk of PCa in diabetics.

METHODS

A systematic literature search (PubMed, Embase and Cochrane Library) identified studies evaluating the associations between ADMs and incidence of PCa. A meta-analysis followed PRISMA was performed using odds ratio (OR) with 95% confidence interval (CI) as effect measures.

RESULTS

In total of 47 studies involving 3,094,152 patients with diabetes were included. Results of meta-analysis of the observational studies suggested no significant association between metformin, thiazolidinediones, sulfonylureas, insulin or dipeptidyl peptidase-4 inhibitors administration and the risk of PCa (All p-values > 0.05). Separate analysis of randomized controlled trials (RCTs) revealed a significant reduction in PCa risk with thiazolidinediones (OR = 0.55, p = 0.04) or glucagon-like peptide-1 receptor agonists (GLP-1RA) administration (OR = 0.53, p = 0.006), whereas no significant association was found in SGLT2 inhibitors (p = 0.3).

CONCLUSION

Thiazolidinediones or GLP-1RA administration may have benefits in PCa based on RCTs, however, further research is needed to confirm these findings.

Glycemic control and the incidence of neoplasm in patients with type 2 diabetes: a meta-analysis of randomized controlled trials

PURPOSE

Previous epidemiologic studies indicate an increased risk of cancer and cancer mortality in patients with type 2 diabetes (T2D). Whether the resolution of hyperglycemia will lead to reduced risk of neoplasm in T2D remains uncertain. Therefore, we performed a meta-analysis to assess the association between glycemic control and incidence of neoplasm in T2D patients.

METHODS

Randomized controlled trials (RCTs) in T2D with significant HbA1c reduction difference between intensive/active and standard/control groups plus follow-up ≥48 weeks were included and analyzed by fixed-effect models, random-effect model, and meta-regression analysis accordingly.

RESULTS

Overall, 52 studies were included. Compared with standard/control treatment, intensive/active treatment led to significantly greater HbA1c reduction from baseline (WMD = -0.51%, 95% CI, -0.55 to -0.46%, P < 0.001), but was not associated with a decreased incidence of neoplasm (OR = 0.99, 95% CI, 0.94-1.03, I² = 2%) in T2D. Meta-regression analysis indicated that HbA1c reduction difference between intensive/active treatment and standard/control treatment was not associated with the incidence of neoplasm in T2D patients (β = -0.0011, 95% CI, -0.0058 to 0.0035, P = 0.625). In neoplasm-site subgroup analysis, a decreased incidence of breast neoplasm was observed in T2D patients using dipeptidyl-peptidase-4 inhibitor (OR = 0.56, 95% CI, 0.35-0.89, I² = 0%) and incidence of prostate neoplasm was reduced in T2D patients with glucagon-like peptide-1 receptor agonist treatment (OR = 0.66, 95% CI, 0.47-0.91, I² = 0%).

CONCLUSION

Improved glycemic control in short and medium periods achieved by existing glucose-lowering drugs or strategies may not confer reduced risk of neoplasm in patients with T2D. Studies with longer follow-up duration are needed to better elucidate the long-period effects.

Genetic deletion of the angiotensin-(1-7) receptor Mas leads to alterations in gut villi length modulating TLR4/PI3K/AKT and produces microbiome dysbiosis

Renin-Angiotensin System (RAS) is an important peptide cascade involved in physiological processes. RAS homeostasis disruption produces several cardiovascular and metabolic disorders, such as arterial hypertension, atherosclerosis, acute myocardial infarct, obesity, diabetes, metabolic syndrome and increases gastrointestinal tract (GIT) cell proliferation. Angiotensin (Ang)-(1-7) peptide is the main RAS counter-regulatory axis effector. It is formed from ACE2 enzyme and acts mainly through Mas receptor (MasR). In this context, the aim of the present study was to evaluate alterations in small intestine morphology and intestinal microbiota composition in MasR knockout C57BL/6 mice. We analyzed glucose tolerance; insulin sensitivity and blood collected for biochemical parameters as well as small intestine tissues samples for immunohistochemistry. mRNA and bacteria gDNA expression evaluation. mRNA expression was evaluated by qRT-PCR for TLR4, PI3K and AKT. The main results showed that Mas-R-knockout mice presented lower body weight. MasR-knockout mice also presented increased fasted blood glucose and total cholesterol with reduced HDL, lower glucose tolerance and impaired insulin sensitivity. Increased intestinal mucosa length, increased intestinal villi, reduced Lieberkühn crypt depth. The increased expression of cell proliferation markers Ki-67 and Cyclin D1 and increased TLR4, PI3K and AKT expressions were observed with augmented Bacteroidetes and decreased amount of Firmicutes. That results suggests that MasR deletion generated changes in intestinal microbiota, possibly due to a lower neutral amino acids absorption followed by a compensatory increase in intestinal villi length associated with disbiosis and LPS overproduction that ultimately lead to proliferation and cell inflammation.

Evolution of Diabetes Care in Hong Kong: From the Hong Kong Diabetes Register to JADE-PEARL Program to RAMP and PEP Program

The rapid increase in diabetes prevalence globally has contributed to large increases in health care expenditure on diabetic complications, posing a major health burden to countries worldwide. Asians are commonly observed to have poorer β-cell function and greater insulin resistance compared to the Caucasian population, which is attributed by their lower lean body mass and central obesity. This "double phenotype" as well as the rising prevalence of young onset diabetes in Asia has placed Asians with diabetes at high risk of cardiovascular and renal complications, with cancer emerging as an important cause of morbidity and mortality. The experience from Hong Kong had demonstrated that a multifaceted approach, involving team-based integrated care, information technological advances, and patient empowerment programs were able to reduce the incidence of diabetic complications, hospitalizations, and mortality. System change and public policies to enhance implementation of such programs may provide solutions to combat the burgeoning health problem of diabetes at a societal level.

Risk for cancer in living kidney donors and recipients

OBJECTIVE

Malignancy following renal transplantation remains inconsistent with the reported safety of kidney donation during the long-term follow-up.

METHODS

We conducted searches of the published literature which included healthy participants, recipients, living kidney donors (LKDs), and the availability of outcome data for malignancy. Eight from 938 potentially relevant studies were analyzed by means of fixed-effects model or random-effects model, as appropriately.

RESULTS

In 48,950 participants, the follow-up range was 18 months to 20 years, and the mean age of the subjects was approximately 41 years. The incidence rate with 95% confidence interval (CI) for malignancy after kidney transplantation was 0.03 (0.01-0.05) in recipients and 0.03 (0.1-0.07) in LKDs, giving a pooled incidence rate of 0.03 (95% CI 0.02-0.04). LKDs contrasted nondonors by the overall odds ratio and 95% CI for total cancer of 2.80 (2.69-2.92).

CONCLUSIONS

Kidney transplantation was associated with an increased risk of cancer during a long-term follow-up. Long-term risk for cancer in LKDs and kidney recipients should be monitored.

Effect of synergistic interaction between abnormal adiposity-related metabolism and prediabetes on microalbuminuria in the general population

Central obesity and related metabolic components are important risks for microalbuminuria. To describe the effects of interactions between central obesity and related metabolic components on microalbuminuria, we conducted a nation-wide, population-based interaction analysis using cardio-metabolic index (CMI) as a candidate indicator of central obesity and related abnormal lipid metabolism. We recruited native Koreans aged 20 years or older with no medical illness. A total of 5398 participants were divided into quintiles according to CMI with sex as a covariate factor. Participants in the highest CMI quintile had elevated blood pressure (BP), increased glycemic exposure, poor lipid profile, and increased urine albumin-to-creatinine ratio compared to other lower quintiles. Multiple logistic regression models adjusted for age, sex, systolic BP, and diastolic BP showed that CMI had an independent association with increased glycemic exposure and increased urine albumin-to-creatinine ratio. Our interaction analysis revealed a significant interaction between the highest CMI quintile and prediabetes with an increased risk of microalbuminuria (adjusted RERI = 0.473, 95% CI = 0.464–0.482; adjusted AP = 0.276, 95% CI = 0.156–0.395; adjusted SI = 2.952, 95% CI = 1.234–4.670). Our findings suggest a significant association between central obesity-related abnormal lipid metabolism and prediabetes, and their interaction may exert a synergistic effect on renal vascular endothelial dysfunction even before the appearance of full-blown diabetes mellitus. To confirm these findings, large population-based prospective studies are needed.

NRF2 activation by antioxidant antidiabetic agents accelerates tumor metastasis

Cancer is a common comorbidity of diabetic patients; however, little is known about the effects that antidiabetic drugs have on tumors. We discovered that common classes of drugs used in type 2 diabetes mellitus, the hypoglycemic dipeptidyl peptidase-4 inhibitors (DPP-4i) saxagliptin and sitagliptin, as well as the antineuropathic α-lipoic acid (ALA), do not increase tumor incidence but increase the risk of metastasis of existing tumors. Specifically, these drugs induce prolonged activation of the nuclear factor E2-related factor 2 (NRF2)-mediated antioxidant response through inhibition of KEAP1-C151-dependent ubiquitination and subsequent degradation of NRF2, resulting in up-regulated expression of metastasis-associated proteins, increased cancer cell migration, and promotion of metastasis in xenograft mouse models. Accordingly, knockdown of NRF2 attenuated naturally occurring and DPP-4i-induced tumor metastasis, whereas NRF2 activation accelerated metastasis. Furthermore, in human liver cancer tissue samples, increased NRF2 expression correlated with metastasis. Our findings suggest that antioxidants that activate NRF2 signaling may need to be administered with caution in cancer patients, such as diabetic patients with cancer. Moreover, NRF2 may be a potential biomarker and therapeutic target for tumor metastasis.

Uric acid, renal function and risk of hypoglycaemia in Chinese type 2 diabetes patients

BACKGROUND

This study aimed to explore independent associations between serum uric acid and hypoglycaemia, and whether mildly increased serum uric acid exacerbated the association between mild decline in estimated glomerular filtration rate (eGFR) and hypoglycaemia.

METHODS

A cross-sectional survey of 6713 inpatients with type 2 diabetes and eGFR ≥60 mL/min/1.73 m² and admitted to 81 tertiary care hospitals in China was conducted. Self-reported asymptotic hypoglycaemia with plasma glucose ≤3.9 mmol/L, hypoglycaemia episodes with symptoms in 1 month or hypoglycaemia that needed assistance from other people in 3 months before hospitalization was used to define hypoglycaemia. Binary logistic regression was used to estimate odds ratios of serum uric acid for hypoglycaemia. Three measures, that is, relative excess risk due to interaction (RERI), attributable proportion due to interaction and synergy index (S) were used to estimate the effect of mildly decreased eGFR on the association of serum uric acid with hypoglycaemia.

RESULTS

Serum uric acid was associated with hypoglycaemia in an ordinal manner (P for trend <0.01) with an odds ratio of top quartile versus the lowest quartile up to 3.03 (95% confidence interval: 2.13-4.32). The odds ratio of serum uric acid levels ≥ versus <283 µmol/L (i.e. the median) was 1.98 (95% confidence interval:1.58-2.48). Serum uric acid levels ≥ versus <283 µmol/L greatly enhanced the association between mild decline in eGFR (eGFR < 90 mL/min/1.73 m² ) and hypoglycaemia from 0.94 (0.36-2.43) to 3.90 (2.55-5.95), with a significant additive interaction (P < 0.05 for RERI, AP and S).

CONCLUSIONS

Mildly increased serum uric acid was associated with increased risk of hypoglycaemia and enhanced the association between mildly decreased eGFR and hypoglycaemia in type 2 diabetes. Copyright © 2016 John Wiley & Sons, Ltd.

Renin-angiotensin system blockade for the risk of cancer and death

INTRODUCTION

The effects of renin-angiotensin system blockade with angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin II type 1 receptor blockers (ARBs) on cancer remain inconsistent.

METHODS

We searched existing databases from 1960 to August 2015, for randomised controlled trials and observational studies (case-control studies and cohort studies) of ARB/ACEI therapy with a minimal one year of follow-up. Outcomes were incidence and mortality of cancer.

RESULTS

We included 14 randomised controlled trials and 17 observational studies of 3,957,725 participants (350,329 ARB/ACEI users). The users had a lower incidence of cancer in the observational studies (RR 0.82, 95% CI 0.73-0.93) but not in the randomised controlled trials (RR 1.00, 95% CI 0.92-1.08). The protection persisted for lung cancer (RR 0.85, 95% CI 0.75-0.97) but not for other sites of cancer. The relative risk of cancer associated with renin-angiotensin system blockade was reduced along with time of follow-up. Mortality reduction with ARB/ACEI was marginally significant in the observational studies (RR 0.71, 95% CI 0.55-0.93) but not in the randomised controlled trials (RR 0.99, 95% CI 0.89-1.09).

CONCLUSIONS

The significant benefits of renin-angiotensin system blockade observed in case-control studies and cohort studies might diminish in randomised controlled trials. Clinical design, site of cancer and duration of follow-up may affect the clinical outcomes.

Statins and the risk of pancreatic cancer in Type 2 diabetic patients--A population-based cohort study

The aim of this study was to determine whether statin use exerts a protective effect against pancreatic cancer in Type 2 diabetic patients. A retrospective population-based cohort study was designed to analyze the National Health Insurance Research database (NHIRD) from 1997-2010 in Taiwan. A total of 1,140,617 patients with a first-time diagnosis of Type 2 diabetes were enrolled. The event was defined as newly diagnosed pancreatic cancer. A Cox proportional hazards regression model with time-dependent covariates was used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) for risk of pancreatic cancer associated with statin use in the diabetic cohort. A total of 2,341 patients with newly diagnosed pancreatic cancer were identified in the diabetic cohort during the follow-up period of 6,968,217.1 person-years. In this cohort, 450,282 patients were defined as statin users (statin use ≥ 28 cumulative defined daily dose [cDDD] in 1 year) and 0.14% had pancreatic cancer; 690,335 patients were statin nonusers (statin use <28 cDDD in 1 year) and 0.25% had pancreatic cancer. Statin use significantly decreased the risk of pancreatic cancer (adjusted HRs: 0.78 in 28-83 cDDD per year; 0.48 in 84-180 cDDD per year; and 0.33 in >180 cDDD per year) after adjusting for multiple confounders. There was a significant dose-effect of statin use for the risk of pancreatic cancer (p for trend: <0.001). Statin use may be associated with a reduced risk of pancreatic cancer in Type 2 diabetic patients. More research is needed to clarify this association.

Drug-subphenotype interactions for cancer in type 2 diabetes mellitus

On the basis of data obtained from a prospective cohort of Chinese patients with type 2 diabetes mellitus (T2DM), we discuss cancer subphenotypes (risk factors) in patients with T2DM, which can lead to drug-cancer subphenotype interactions. These subphenotypes include HDL cholesterol levels <1.0 mmol/l, co-occurrence of LDL cholesterol levels <2.8 mmol/l and triglyceride levels <1.7 mmol/l, and co-occurrence of LDL cholesterol levels <2.8 mmol/l and albuminuria. The increased risk of cancer associated with low levels of HDL cholesterol, low LDL cholesterol levels plus low triglyceride levels, and low levels of LDL cholesterol plus albuminuria can be reduced by treatment with metformin, renin-angiotensin system (RAS) inhibitors and statins, respectively. Mechanistic studies support the hypothesis that dysregulation of the 5'-AMP-activated protein kinase pathway and crosstalk between the RAS and insulin-like growth factor 1-cholesterol pathways create a cancer-promoting milieu in patients with T2DM. These findings highlight that in Chinese individuals, multiple pathways are implicated in the link between T2DM and cancer, which can generate multiple subphenotypes as well as drug-subphenotype interactions.

Renin angiotensin system inhibitors may attenuate low LDL cholesterol-related cancer risk in type 2 diabetes

BACKGROUND

In type 2 diabetes (T2D), copresence of low-density lipoprotein cholesterol (LDL-C) < 2.8 mmol/L with triglyceride < 1.7 mmol/L or with albuminuria synergistically increased cancer risk. We tested whether use of renin angiotensin system inhibitors attenuated the increased cancer risk associated with these two risk subphenotypes.

METHODS

A prospective cohort of 4307 patients with T2D enrolled from December 1996 to January 2005 was analysed using a new user cohort design. Cox model analysis was used to obtain hazard ratios and 95% confidence intervals. The study measured additive interactions between nonuse of renin angiotensin system inhibitors and low LDL-C plus low triglyceride or albuminuria for the risk of cancer. A positive interaction suggests a specific drug effect on the low LDL-C-related cancer risk.

RESULTS

During 18 769 person years of follow-up (median follow-up years: 4.44), 4.48% (n = 193) of patients developed cancer. Use of renin angiotensin system inhibitors was associated with reduced cancer risk among patients with copresence of low LDL-C plus low triglyceride or low LDL-C plus albuminuria but not in patients without these subphenotypes. In multivariable analysis, renin angiotensin system inhibitor usage attenuated the hazard ratio of copresence of low LDL-C plus low triglyceride versus lack of this subphenotype for cancer from 2.08 (95% CI: 1.25-3.47) to 1.13 (0.61-2.11) with significant additive interaction (p = 0.0225). Similarly, RAS inhibitor usage attenuated the hazard ratio of copresence of low LDL-C plus albuminuria versus lack of this subphenotype for cancer from 1.99 (95% CI: 1.12-3.56) to 0.82 (0.43-1.54) with significant additive interaction (p = 0.0009).

CONCLUSION

In T2D, renin angiotensin system inhibitor usage may specifically attenuate the low LDL-C-related cancer risk.

Additive effects of blood glucose lowering drugs, statins and renin-angiotensin system blockers on all-site cancer risk in patients with type 2 diabetes

BACKGROUND

Hyperglycemia is associated with increased risk of all-site cancer that may be mediated through activation of the renin-angiotensin-system (RAS) and 3-hydroxy-3-methyl-glutaryl-coenzyme-A-reductase (HMGCR) pathways. We examined the joint associations of optimal glycemic control (HbA1c <7%), RAS inhibitors and HMGCR inhibitors on cancer incidence in patients with type 2 diabetes.

METHODS

Patients with type 2 diabetes, with or without a history of cancer or prior exposure to RAS or HMGCR inhibitors at baseline were observed between 1996 and 2005. All patients underwent a comprehensive assessment at baseline and were followed until the censored date at 2005 or their death.

RESULTS

After a median follow-up period of 4.91 years (interquartile range, 2.81 to 6.98), 271 out of 6,103 patients developed all-site cancer. At baseline, patients with incident cancers were older, had longer disease duration of diabetes, higher alcohol and tobacco use, and higher systolic blood pressure and albuminuria, but lower triglyceride levels and estimated glomerular filtration rate (P <0.05). Patients who developed cancers during follow-up were less likely to have started using statins (22.5% versus 38.6%, P <0.001), fibrates (5.9% versus 10.2%, P = 0.02), metformin (63.8% versus 74.5%, P <0.001) or thiazolidinedione (0.7% versus 6.8%, P <0.001) than those who remained cancer-free. After adjusting for co-variables, new treatment with metformin (hazard ratio: 0.39; 95% confidence interval: 0.25, 0.61; P <0.001), thiazolidinedione (0.18; 0.04, 0.72; P = 0.015), sulphonylurea (0.44; 0.27, 0.73; P = 0.014), insulin (0.58; 0.38, 0.89; P = 0.01), statins (0.47; 0.31, 0.70; P <0.001) and RAS inhibitors (0.55; 0.39, 0.78; P <0.001) were associated with reduced cancer risk. Patients with all three risk factors of HbA1c ≥7%, non-use of RAS inhibitors and non-use of statins had four-fold adjusted higher risk of cancer than those without any risk factors (incidence per 1,000-person-years for no risk factors: 3.40 (0.07, 6.72); one risk factor: 6.34 (4.19, 8.50); two risk factors: 8.40 (6.60, 10.20); three risk factors: 13.08 (9.82, 16.34); P <0.001).

CONCLUSIONS

Hyperglycemia may promote cancer growth that can be attenuated by optimal glycemic control and inhibition of the RAS and HMGCR pathways.

Genetic variants for type 2 diabetes and new-onset cancer in Chinese with type 2 diabetes

BACKGROUND

Diabetes is associated with an increased risk of cancer. This study aimed to evaluate associations between recently reported type 2 diabetes (T2D) susceptibility genetic variants and cancer risk in a prospective cohort of Chinese patients with T2D.

METHODS

Seven single nucleotide polymorphisms (SNP) in IGF2BP2, CDKAL1, SLC30A8, CDKN2A/B, HHEX and TCF7L2, all identified from genome-wide association studies of T2D, were genotyped in 5900 T2D patients [age mean ± SD = 57 ± 13 years, % males = 46] without any known cancer at baseline. Associations between new-onset of cancer and SNPs were tested by Cox proportional hazard models with adjustment of conventional risk factors.

RESULTS

During the mean follow-up period of 8.5 ± 3.3 years, 429 patients (7.3%) developed cancer. Of the T2D-related SNPs, the G-alleles of HHEX rs7923837 (hazard ratio [HR] (95% C.I.) = 1.34 (1.08-1.65); P = 6.7 ×10(-3) under dominant model) and TCF7L2 rs290481 (HR (95% C.I.) = 1.16 (1.01-1.33); P = 0.040 under additive model) were positively associated with cancer risk, while the G-allele of CDKAL1 rs7756992 was inversely associated (HR (95% C.I.) = 0.80 (0.65-1.00); P = 0.048 under recessive model). The risk alleles of these significant SNPs exhibited combined effect on increasing cancer risk (per-allele HR (95% C.I.) = 1.25 (1.12-1.39); P = 4.8 × 10(-5)). The adjusted cancer risk was 2.41 (95% C.I. 1.23-4.69) for patients with four risk alleles comparing to patients without risk allele.

CONCLUSIONS

T2D-related variants HHEX rs7923837, TCF7L2 rs290481 and CDKAL1 rs7756992 increased cancer risk in patients with diabetes.

IMPACT

Our findings provide novel insights into the pathogenesis of cancer in diabetes.

Enhancers and attenuators of risk associations of chronic hepatitis B virus infection with hepatocellular carcinoma in type 2 diabetes

Chronic hepatitis B virus (HBV) infection promotes hepatocellular carcinoma (HCC) risk. In type 2 diabetes (T2D), use of insulin and statins was associated with reduced cancer risk while co-presence of low LDL cholesterol (LDLC <2.8 mmol/l) plus low triglyceride (TG; <1.7 mmol/l) increased cancer risk. There is experimental evidence showing that insulin insufficiency might promote HCC. In this study, we examined whether this lipid subphenotype and use of insulin or statins might modify the promoting effect of chronic HBV infection (indicated by the presence of hepatitis B surface antigen) on HCC. We analyzed data of 1319 T2D patients enrolled into the Hong Kong Diabetes Registry from December 1996 to January 2005 and followed up to 2005. Additive interaction was estimated using relative excess risk due to interaction and attributable proportion due to interaction. During 5782 person-years of follow-up, 1.74% (n=23) of patients developed HCC (incidence, 3.98; 95% confidence interval, 2.36-5.60/1000 person-years). HbA1c ≥7.0% and the lipid phenotype (LDLC <2.8 mmol/l plus TG <1.7 mmol/l) increased the hazard ratios (HRs) of chronic HBV infection for HCC from 3.74 to 74.96 and from 11.01 to 89.82 respectively with significant interactions. Use of insulin or statins decreased the HRs from 37.51 to 5.87 and from 64.94 to 16.99 respectively with significant interactions (all P values <0.05). These findings support our hypothesis that hyperglycemia and co-presence of low LDLC plus low TG might enhance, while insulin or statin usage might attenuate the promoting effect of chronic HBV infection on HCC in T2D.

Clinical outcomes of chemotherapy for diabetic and nondiabetic patients with pancreatic cancer: better prognosis with statin use in diabetic patients

OBJECTIVES

The aim of this study was to clarify the impact of diabetes mellitus (DM) as well as antidiabetic, antihypertensive, and antihyperlipidemic medications such as metformin and statins on survival in patients with advanced pancreatic cancer receiving chemotherapy.

METHODS

We retrospectively reviewed the medical records of 250 patients with advanced pancreatic cancer receiving chemotherapy. Multivariate analyses of prognostic factors for survival were performed both in overall population and in subgroups with and without DM.

RESULTS

Diabetes mellitus was diagnosed in 124 patients (50%) who had less distant metastasis and more hypertension. Thirty patients received statin for hyperlipidemia. Overall survival was 13.3 versus 10.0 months with and without DM (P = 0.084), but hazard ratio of DM was 1.05 (P = 0.758) in the multivariate analysis. Subgroup analysis of diabetic patients, but not in non-diabetic patients, demonstrated use of statins (hazard ratio, 0.40; P = 0.010) as a prognostic factor, as well as distant metastasis, performance status, combination therapy with gemcitabine and S-1, and use of angiotensin-converting enzyme inhibitors or angiotensin receptor blockers. No antidiabetic medications were prognostic factors.

CONCLUSIONS

Neither DM nor antidiabetic treatment had prognostic impact on advanced pancreatic cancer. Statin use was associated with better survival in the diabetic patients.

Statins and the risk of gastric cancer in diabetes patients

Background

Several studies have suggested a cancer risk reduction in statin users although the evidence remains weak for stomach cancer. The purpose of this study was to use an exact-matching case–control design to examine the risk of gastric cancer associated with the use of statins in a cohort of patients with diabetes.

Methods

Cases were defined as patients with incident gastric cancer identified by International Classification of Diseases 16.0 ~ 16.9 recorded at Samsung Medical Center database during the period of 1999 to 2008, at least 6 months after the entry date of diabetes code. Each gastric cancer case patient was matched with one control patient from the diabetes patient registry in a 1:1 fashion, blinded to patient outcomes.

Results

A total of 983 cases with gastric cancer and 983 controls without gastric cancer, matched by age and sex, were included in the analysis. The presence of prescription for any statin was inversely associated with gastric cancer risk in the unadjusted conditional logistic regression model (OR: 0.18; 95% CI: 0.14 – 0.24; P < .0001). Multivariate analysis using conditional logistic regression with Bonferroni’s correction against aspirin indicated a significant reduction in the risk of gastric cancer in diabetes patients with statin prescriptions (OR: 0.21; 95% CI: 0.16 – 0.28; P < .0001). After adjustment for aspirin use, a longer duration of statin use was associated with reduced risk of gastric cancer, with statistical significance (P<.0001).

Conclusions

A strong inverse association was found between the risk of gastric adenocarcinoma and statin use in diabetic patients.

Synergistic effects of low LDL cholesterol with other factors for the risk of cancer in type 2 diabetes: the Hong Kong Diabetes Registry

We have reported associations of cancer with low triglyceride and high high-density lipoprotein cholesterol (HDL-C) as well as co-presence of low low-density lipoprotein cholesterol (LDL-C) and albuminuria in type 2 diabetes (T2D). This analysis aims to test (1) whether low LDL-C and low triglyceride have synergistic effects to increase cancer risk in T2D and (2) whether high HDL-C enhances the effect of co-presence of low LDL-C and albuminuria on cancer risk. A prospective cohort of patients with T2D, established within the Prince of Wales Hospital, was used in the analysis. A total of 3,476 T2D patients in Hong Kong enrolled between 1996 and 2005, free of cancer at enrolment and not using statins or fibrates within 2.5 years before enrolment and during follow-up, were followed until 2005. The study measured additive interactions of low LDL-C with other factors for cancer using relative excess risk due to interaction (RERI) and attributable proportion due to interaction (AP). A statistically significant RERI > 0 or AP > 0 indicates additive interaction. During 5.11 years of follow-up, 199 patients developed cancer. Co-presence of triglyceride <1.70 mmol/L and LDL-C < 2.80 mmol/L was associated with increased cancer risk (multivariable hazard ratio [HR]:2.13, P = 0.0008) with significant interaction. Co-presence of HDL-C ≥ 1.30 mmol/L and LDL-C < 2.80 mmol/L plus albuminuria was also associated with increased cancer risk (HR: 3.84, P < 0.0001) with significant interaction. In T2D, low triglyceride may potentiate cancer risk associated with low LDL-C while high HDL-C enhances the synergistic effect of low LDL-C with albuminuria towards increased cancer risk.

Addressing different biases in analysing drug use on cancer risk in diabetes in non-clinical trial settings--what, why and how?

Motivated by recent reports on associations between diabetes and cancer, many researchers have used administrative databases to examine risk association of cancer with drug use in patients with diabetes. Many of these studies suffered from major biases in study design and data analysis, which can lead to erroneous conclusions if these biases are not adjusted. This article discusses the sources and impacts of these biases and methods for correction of these biases. To avoid erroneous results, this article suggests performing sensitivity and specificity analysis as well as using a drug with a known effect on an outcome to ascertain the validity of the proposed methods. Using the Hong Kong Diabetes Registry, we illustrated the impacts of biases of drug use indication and prevalent user by examining the effects of statins on cardiovascular disease. We further showed that 'immortal time bias' may have a neutral impact on the estimated drug effect if the hazard is assumed to be constant over time. On the contrary, adjustment for 'immortal time bias' using time-dependent models may lead to misleading results biased towards against the treatment. However, artificial inclusion of immortal time in non-drug users to correct for immortal time bias may bias the result in favour of the therapy. In conclusion, drug use indication bias and prevalent user bias but not immortal time bias are major biases in the design and analysis of drug use effects among patients with diabetes in non-clinical trial settings.

Diabetes and cancer: the mechanistic implications of epidemiological analyses from the Hong Kong Diabetes Registry

Diabetes is a disorder of energy metabolism associated with increased cancer risk, but the underlying mechanism is poorly understood. In a prospective cohort of patients enrolled in the Hong Kong Diabetes Registry, we explored risk factors for cancer including drug usage in type 2 diabetes. In a series of published papers, we reported a linear risk association of cancer with glycated haemoglobin with a threshold at 6.0%-6.5% and non-linear risk associations of body mass index, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, triglyceride and white blood cell (WBC) count in V-shaped or A-shaped manners. Detailed pharmacoepidemiological analysis revealed markedly attenuated cancer risk in patients treated with insulin and oral anti-diabetic drugs compared with non-users of these drugs. We further observed significant drug-subphenotype interactions with attenuated cancer risk in metformin users with low high-density lipoprotein cholesterol, renin-angiotensin system (RAS) inhibitor users with high WBC count and statin users with co-presence of low low-density lipoprotein cholesterol plus albuminuria or low triglyceride. These novel observations corroborate with experimental findings of possible consequences of hyperglycaemia on dysregulation of cholesterol metabolism, renin-angiotensin system and adenosine 5'-monophosphate-activated protein kinase pathways, all of which may be implicated in carcinogenesis. On the basis of these epidemiological and experimental findings, we argue for the strong need to strengthen the health care system to ensure that type 2 diabetes subjects receive appropriate drugs to optimize internal milieu to reduce all events including cancer. Apart from mechanistic studies, large-scale, randomized clinical trials using medications such as statin, renin-angiotensin system inhibitors and metformin in patients with risk-conferring subphenotypes are needed to confirm their anti-cancer effects.

Diabetes, insulin and cancer risk

There is a consensus that both type 1 and type 2 diabetes are associated with a spectrum of cancers but the underlying mechanisms are largely unknown. On the other hand, there are ongoing debates about the risk association of insulin use with cancer. We have briefly reviewed recent related research on exploration of risk factors for cancer and pharmacoepidemiological investigations into drug use in diabetes on the risk of cancer, as well as the current understanding of metabolic pathways implicated in intermediary metabolism and cellular growth. Based on the novel findings from the Hong Kong Diabetes Registry and consistent experimental evidence, we argue that use of insulin to control hyperglycemia is unlikely to contribute to increased cancer risk and that dysregulations in the AMP-activated protein kinase pathway due to reduced insulin action and insulin resistance, the insulin-like growth factor-1 (IGF-1)-cholesterol synthesis pathway and renin-angiotensin system, presumably due to reduced insulin secretion and hyperglycemia, may play causal roles in the increased risk of cancer in diabetes. Further exploration into the possible causal relationships between abnormalities of these pathways and the risk of cancer in diabetes is warranted.

Sustained antidiabetic effects of a berberine-containing Chinese herbal medicine through regulation of hepatic gene expression

Diabetes and obesity are complex diseases associated with insulin resistance and fatty liver. The latter is characterized by dysregulation of the Akt, AMP-activated protein kinase (AMPK), and IGF-I pathways and expression of microRNAs (miRNAs). In China, multicomponent traditional Chinese medicine (TCM) has been used to treat diabetes for centuries. In this study, we used a three-herb, berberine-containing TCM to treat male Zucker diabetic fatty rats. TCM showed sustained glucose-lowering effects for 1 week after a single-dose treatment. Two-week treatment attenuated insulin resistance and fatty degeneration, with hepatocyte regeneration lasting for 1 month posttreatment. These beneficial effects persisted for 1 year after 1-month treatment. Two-week treatment with TCM was associated with activation of AMPK, Akt, and insulin-like growth factor-binding protein (IGFBP)1 pathways, with downregulation of miR29-b and expression of a gene network implicated in cell cycle, intermediary, and NADPH metabolism with normalization of CYP7a1 and IGFBP1 expression. These concerted changes in mRNA, miRNA, and proteins may explain the sustained effects of TCM in favor of cell survival, increased glucose uptake, and lipid oxidation/catabolism with improved insulin sensitivity and liver regeneration. These novel findings suggest that multicomponent TCM may be a useful tool to unravel genome regulation and expression in complex diseases.

The Complexity of Vascular and Non-Vascular Complications of Diabetes: The Hong Kong Diabetes Registry

Diabetes is a complex disease characterized by chronic hyperglycemia and multiple phenotypes. In 1995, we used a doctor-nurse-clerk team and structured protocol to establish the Hong Kong Diabetes Registry in a quality improvement program. By 2009, we had accrued 2616 clinical events in 9588 Chinese type 2 diabetic patients with a follow-up duration of 6 years. The detailed phenotypes at enrollment and follow-up medications have allowed us to develop a series of risk equations to predict multiple endpoints with high sensitivity and specificity. In this prospective database, we were able to validate findings from clinical trials in real practice, confirm close links between cardiovascular and renal disease, and demonstrate the emerging importance of cancer as a leading cause of death. In addition to serving as a tool for risk stratification and quality assurance, ongoing data analysis of the registry also reveals secular changes in disease patterns and identifies unmet needs.

Low HDL cholesterol, metformin use, and cancer risk in type 2 diabetes: the Hong Kong Diabetes Registry

OBJECTIVE

The AMP-activated protein kinase (AMPK) pathway is a master regulator in energy metabolism and may be related to cancer. In type 2 diabetes, low HDL cholesterol predicts cancer, whereas metformin usage is associated with reduced cancer risk. Both metformin and apolipoprotein A1 activate the AMPK signaling pathway. We hypothesize that the anticancer effects of metformin may be particularly evident in type 2 diabetic patients with low HDL cholesterol.

RESEARCH DESIGN AND METHODS

In a consecutive cohort of 2,658 Chinese type 2 diabetic patients enrolled in the study between 1996 and 2005, who were free of cancer and not using metformin at enrollment or during 2.5 years before enrollment and who were followed until 2005, we measured biological interactions for cancer risk using relative excess risk as a result of interaction (RERI) and attributable proportion (AP) as a result of interaction. A statistically significant RERI >0 or AP >0 indicates biological interaction.

RESULTS

During 13,808 person-years of follow-up (median 5.51 years), 129 patients developed cancer. HDL cholesterol <1.0 mmol/L was associated with increased cancer risk among those who did not use metformin, but the association was not significant among those who did. Use of metformin was associated with reduced cancer risk in patients with HDL cholesterol <1.0 mmol/L and, to a lesser extent, in patients with HDL cholesterol ≥ 1.0 mmol/L. HDL cholesterol <1.0 mmol/L plus nonuse of metformin was associated with an adjusted hazard ratio of 5.75 (95% CI 3.03-10.90) compared with HDL cholesterol ≥ 1.0 mmol/L plus use of metformin, with a significant interaction (AP 0.44 [95% CI 0.11-0.78]).

CONCLUSIONS

The anticancer effect of metformin was most evident in type 2 diabetic patients with low HDL cholesterol.

Use of sulphonylurea and cancer in type 2 diabetes-The Hong Kong Diabetes Registry

BACKGROUND

Hyperglycaemia is a risk factor for cancer and some sulphonylureas have anti-oxidant properties. This study examined associations between use of sulphonylureas and cancer.

METHODS

A consecutive cohort of 6103 Hong Kong Chinese patients with T2DM, free of cancer, was analysed using Cox models. Sulphonylurea usage was defined as use of the drugs at or within 2.5 years before enrolment and/or during follow-up periods. We adjusted for identified risk factors of cancer, use of other drugs, non-linear associations of lipids with cancer and probabilities of use of these drugs at different times and doses where appropriate.

RESULTS

During a median of 4.91 years of follow-up, 271 developed cancer. Glibenclamide, gliclazide and glipizide were ever used in 32.5% (n = 1983), 47.8% (n = 2920) and 13.5% (n = 823). After adjustment for covariates, use of gliclazide and glibenclamide was associated with reduced cancer risk in a dose-dependent manner. In addition, there were interactions between metformin and glibenclamide/glipizide use towards lower adjusted cancer risks.

CONCLUSIONS

In T2DM, use of glibenclamide and gliclazide may be associated with reduced cancer risk.

Low triglyceride and nonuse of statins is associated with cancer in type 2 diabetes mellitus: the Hong Kong Diabetes Registry

BACKGROUND

Patients with type 2 diabetes mellitus (T2DM) have increased cancer risks. The authors reported nonlinear associations of cancer with triglyceride and other lipids in T2DM. Crosstalk between lipid metabolism and the renin-angiotensin system may increase cancer risk via activation of insulin-like growth factor-1 pathway in T2DM. In this analysis, the authors explored associations of cancer risk with high/low triglyceride in T2DM and possible modifying effects of statins on this risk association, if any.

METHODS

A consecutive cohort of 5166 Chinese patients with T2DM, free of cancer at enrollment and not using statins at or before enrollment, was analyzed using Cox models. Biological interactions were estimated using relative excess risk because of interaction, attributable proportion because of interaction, and synergy index. Relative excess risk because of interaction > 0, attributable proportion because of interaction > 0, or synergy index > 1 indicates biological interaction.

RESULTS

During 5.25 years of follow-up (median), 4.7% (n = 243) patients developed cancer. Triglyceride < 1.70 mmol/L was associated with increased cancer risk in the entire cohort and in statin nonusers, but not in statin users. Patients with triglyceride < 1.70 mmol/L plus nonuse of statins during follow-up had 2.74-fold increased cancer risk compared with their counterparts with either triglyceride ≥ 1.70 mmol/L or use of statins or both. There was significant interaction between triglyceride < 1.70 mmol/L and nonuse of statins (relative excess risk because of interaction, 0.99; 95% confidence interval [CI], 0.07-1.90 and attributable proportion because of interaction, 0.36; 95% CI, 0.02-0.70).

CONCLUSIONS

In Chinese T2DM patients, triglyceride < 1.70 mmol/L might be associated with increased cancer risk, which was attenuated in the presence of use of statins.

Associations of hyperglycemia and insulin usage with the risk of cancer in type 2 diabetes: the Hong Kong diabetes registry

OBJECTIVE Insulin has mitogenic effects, although hyperglycemia may be a risk factor for cancer in type 2 diabetes. It remains uncertain whether use of insulin increases cancer risk because of its effect on cell growth and proliferation or decreases cancer risk because of its glucose-lowering effect. RESEARCH DESIGN AND METHODS A 1:2-matched new insulin user cohort on age (+/-3 years), smoking status, and likelihood of initiating insulin therapy (+/-0.05) was selected from a cohort of 4,623 Chinese patients with type 2 diabetes, free of cancer, and naive to insulin at enrollment. Stratified Cox regression analysis on the matched pairs was used to obtain hazard ratios (HRs) of insulin therapy and A1C for cancer risk. A structured adjustment scheme was used to adjust for covariates. RESULTS Of 973 new insulin users, 971 had matched nonusers (n = 1935). The cancer incidence in insulin nonusers was much higher than that in insulin users (49.2 vs. 10.2, per 1,000 person-years, P < 0.0001). After further adjustment for all other covariates with a P value less than 0.3 and nonlinear associations with cancer, A1C was associated with an increased cancer risk (HR per percentage 1.26, 95% CI 1.03-1.55), whereas use of insulin was associated with a decreased cancer risk (HR of insulin users vs. nonusers: 0.17, 0.09-0.32). Consistent results were found in analyses including all 973 insulin users and 3,650 nonusers. CONCLUSIONS In Chinese patients with type 2 diabetes, hyperglycemia predicts cancer, whereas insulin usage was associated with a reduced cancer risk.

White blood cell count and renin-angiotensin system inhibitors for the risk of cancer in type 2 diabetes

BACKGROUND

High white blood cell (WBC) predicted cancer-associated mortality and renin-angiotensin system (RAS) inhibitors have immunomodulating effects. We hypothesize that RAS inhibitors may reduce cancer risk associated with high WBC in type 2 diabetes mellitus (T2DM).

METHODS

A prospective cohort of 4570 Chinese T2DM patients, free of cancer at enrolment, were analyzed. Biological interaction between WBC groups and use of RAS inhibitors was estimated using relative excess risk due to interaction (RERI), attributable proportion due to interaction (AP) and synergy index (S). RERI>0, AP>0 or S>1 indicates biological interaction.

RESULTS

During 4.89 years of follow-up, 205 (4.49%) patients developed cancer. WBC > or = 8.2 x 10(9) counts/L plus non-use of RAS inhibitors was associated with elevated cancer risks in multivariable models. The RERI and AP for interaction between WBC > or = 8.2 x 10(9) counts/L and non-use of RAS inhibitors were, respectively, 1.26 (95% CI: 0.22-2.31) and 0.50 (0.23-0.78). In patients with WBC > or = 8.2 x 10(9) counts/L, use of RAS inhibitors was associated with 64% (31-81%) cancer risk reduction in multivariable analysis.

CONCLUSIONS

In T2DM, increased WBC predicts cancer while use of RAS inhibitors may reduce cancer risks associated with high WBC count.