Smoking and progression of diabetic nephropathy in patients with type 1 diabetes

Incidence and risk factors for cancer in people with type 1 diabetes, stratified by stages of diabetic kidney disease: a nationwide Finnish cohort study

Background

Individuals with type 1 diabetes (T1D) have been reported to have increased overall risk of cancer. In addition, individuals with a kidney transplant/transplantation (KT) have markedly increased cancer risk due to chronic use of immunosuppressive agents. However, it has not been elucidated whether the observed excess cancer risk is related to KT or whether diabetic kidney disease (DKD) per se is a risk factor for cancer in individuals with T1D.

Methods

The study included 5035 individuals from the Finnish Diabetic Nephropathy Study (FinnDiane) and 14,061 control individuals without diabetes. We assessed the standardized incidence ratios (SIRs) for cancers in individuals with T1D compared to controls according to DKD status. Cox regression analyses were used to identify potential risk factors for cancer in individuals with type 1 diabetes.

Findings

The SIR for overall cancer for all participants was 1.14 (1.05-1.24), for participants without KT 0.92 (0.83-1.01) and for participants with KT 4.78 (4.02-5.64). Participants without KT had in fact a reduced risk of prostate cancer with a SIR of 0.54 (0.37-0.76), cancer of urinary organs 0.41 (0.21-0.73) and respiratory and intrathoracic organs, 0.62 (0.38-0.97). Participants with KT had on the contrary an increased risk of non-melanoma skin cancer, SIR 14.50 (10.99-18.86), cancer in the lymphoid and hematopoietic tissue 5.38 (2.99-8.96), mouth or pharynx 5.13 (2.08-10.66), melanoma 5.12 [2.38-9.72]) and respiratory and intrathoracic organs 2.77 (1.21-5.49). The risk of thyroid cancer was increased both in participants without KT, SIR 2.14 (1.39-3.16) and with KT 5.30 (1.68-12.78).

Interpretation

The excess overall cancer risk in individuals with type 1 diabetes is only seen in KT recipients and in thyroid cancer. The individuals without KT seem to have a decreased risk of some forms of cancer.

Funding

Folkhälsan Research Foundation, Academy of Finland [316664], Wilhelm and Else Stockmann Foundation, Liv och Hälsa Society, Novo Nordisk Foundation [NNF OC0013659], Finnish Foundation for Cardiovascular Research, Finnish Diabetes Research Foundation, Medical Society of Finland, Sigrid Jusélius Foundation, and Helsinki University Hospital Research Funds [TYH2018207 and TYH 2020305].

RISK FACTORS FOR DIABETIC NEPHROPATHY IN DIABETES MELLITUS TYPE 1

OBJECTIVE

The aim: To find the risk factors of microalbuminuria and estimated Glomerular Filtration Rate (eGFR) in patients with type 1 diabetes mellitus.

PATIENTS AND METHODS

Materials and methods: One hundred ten patients of type 1 diabetes mellitus in this cross-sectional study at diabetic and endocrinology center in Al-Najaf during the period from September 2021 to March 2022. All patients were asked about sociodemographic characteristics (age, gender, smoking, duration of DM type1, family history of DM type1), measured (body mass index BMI, blood pressure) and laboratory investigations done to all patients (G.U.E, s. creatinine, lipid profile, HBA1C, calculated estimated Glomerular Filtration Rate (eGFR) and Spot Urine Albumin-Creatinine Ratio (ACR).

RESULTS

Results: Out of 110 patients, 62 male and 48 female, the mean age was (22±12). The patients with microalbuminuria (ACR ≥ 30 mg/g) show statistically significant with increase HBA1C, duration of DM type 1, total cholesterol (T.C), low density lipoprotein (LDL), triglycerides (TG) and family history of DM type 1, while there were not statistically significant with age, gender, smoking, BMI, eGFR, high density lipoprotein (HDL) and hypertension. Patients with eGFR<90mL/min/1.73m2 show statistically significant with increase HBA1C, duration of DM type1, LDL, TG, T.C, while significantly decrease in HDL and there were not statistically significant with age, gender, smoking, family history of DM type 1, BMI and hypertension.

CONCLUSION

Conclusions: The degree of glycemic control, duration of type1 (DM) and dyslipidemia were associated with increased microalbuminuria and reduced eGFR (nephropathy). Family history of DM type1 was risk factor for microalbuminuria.

Carotid ultrasonography as a strategy to optimize cardiovascular risk management in type 1 diabetes: a cohort study

BACKGROUND AND AIMS

Although cardiovascular disease (CVD) remains the leading cause of mortality in type 1 diabetes (T1D), the use of cardioprotective drugs is scarce. We aimed to evaluate the impact of carotid ultrasonography (US) on the improvement in cardiovascular risk factors (CVRFs) in T1D.

METHODS AND RESULTS

T1D patients without CVD meeting criteria for lipid treatment according to guidelines (age ≥ 40 years, nephropathy and/or ≥ 10 years of diabetes duration with ≥ 1 additional CVRFs) were included. The carotid-US group (US-G) underwent a standardized US protocol and CVRF assessment; recommendations were made according to subclinical atherosclerosis status. The control group (CG) followed usual clinical practice. Changes in CVRFs, specially statin use and LDL cholesterol levels, at 1 year were analysed. A total of 318 patients were included (51.3% female, mean age of 49.1 years and 25.5 years of diabetes duration): 211 in the US-G and 107 in the CG. Participants in the US-G had a higher baseline LDL cholesterol than controls (114 vs. 102 mg/dL; p < 0.001). Lipid-lowering treatment was modified in 38.9% in the US-G and 6.5% in the CG (p < 0.001). At 1 year, the US-G was more frequently on statins, had lower LDL cholesterol and 27% had stopped smoking (p < 0.001 for all). Changes were more pronounced in those with plaques (p < 0.001). In multivariate analyses adjusted for age, sex and other CVRFs, belonging to the US-G was independently associated with the intensification of lipid-lowering treatment (OR 10.47 [4.06-27.01]). Propensity score-matching analysis yielded similar results (OR 20.09 [7.86-51.37]).

CONCLUSION

Carotid-US is independently associated with an intensification of lipid-lowering therapy in a high-risk T1D population.

Smoking and diabetes interplay: A comprehensive review and joint statement

Evidence shows that smoking increases the risk of pre-diabetes and diabetes in the general population. Among persons with diabetes, smoking has been found to increase the risk of all-cause mortality and aggravate chronic diabetic complications and glycemic control. The current paper, which is a joint position statement by the French-Speaking Society on Tobacco (Société Francophone de Tabacologie) and the French-Speaking Society of Diabetes (Société Francophone du Diabète), summarizes the data available on the association between smoking and diabetes and on the impact of smoking and smoking cessation among individuals with type 1, type 2, and gestational diabetes mellitus. It also provides evidence-based information about the pharmacological and behavioral strategies for smoking cessation in these patients.

Xenobiotics Delivered by Electronic Nicotine Delivery Systems: Potential Cellular and Molecular Mechanisms on the Pathogenesis of Chronic Kidney Disease

Chronic kidney disease (CKD) is characterized as sustained damage to the renal parenchyma, leading to impaired renal functions and gradually progressing to end-stage renal disease (ESRD). Diabetes mellitus (DM) and arterial hypertension (AH) are underlying diseases of CKD. Genetic background, lifestyle, and xenobiotic exposures can favor CKD onset and trigger its underlying diseases. Cigarette smoking (CS) is a known modified risk factor for CKD. Compounds from tobacco combustion act through multi-mediated mechanisms that impair renal function. Electronic nicotine delivery systems (ENDS) consumption, such as e-cigarettes and heated tobacco devices, is growing worldwide. ENDS release mainly nicotine, humectants, and flavorings, which generate several byproducts when heated, including volatile organic compounds and ultrafine particles. The toxicity assessment of these products is emerging in human and experimental studies, but data are yet incipient to achieve truthful conclusions about their safety. To build up the knowledge about the effect of currently employed ENDS on the pathogenesis of CKD, cellular and molecular mechanisms of ENDS xenobiotic on DM, AH, and kidney functions were reviewed. Unraveling the toxic mechanisms of action and endpoints of ENDS exposures will contribute to the risk assessment and implementation of proper health and regulatory interventions.

Impact of stopping smoking on metabolic parameters in diabetes mellitus: A scoping review

The purpose of this scoping review is to create a single narrative that describes the impact of smoking cessation on metabolic parameters in people with diabetes. It is generally well accepted that smoking enhances the harmful effects of elevated blood glucose levels, accelerating the vascular damage seen in patients with diabetes. Smoking cessation has clear benefits in terms of reducing cardiovascular morbidity and mortality. However, there is less evidence for the impact of smoking cessation on other diabetes-related complications. Studies in people with diabetes have shown improvement as well as temporary deterioration in glycemic control after ceasing smoking. Only a few studies have described the effect of quitting smoking on insulin resistance and lipid parameters, however, their results have been inconclusive. In this situation, healthcare professionals should not assume that cessation of smoking will improve metabolic parameters in patients with diabetes. It seems they should, first of all, emphasize the prevention of weight gain that may be associated with quitting smoking. The lack of data regarding the metabolic effects of smoking and smoking cessation in diabetes is very disappointing and this area needs to be addressed.

Tobacco use patterns and clinical outcomes in the T1D exchange

AIMS

This study examined associations between tobacco use and diabetes outcomes using the T1D Exchange Registry.

METHODS

Adult participants (N = 933) completed standardized questionnaires including self-reported outcomes: past year serious hypoglycemic and diabetic ketoacidosis episodes, diabetes self-care, diabetes distress, and self-monitoring of blood glucose. Chart-extracted outcomes included HbA1c, nephrology and neuropathy diagnoses, and BMI. We examined the relation of tobacco use status (never, former, current) and frequency of use (daily versus less than daily) to these outcomes.

RESULTS

The majority had never used tobacco (55%, n = 515); 27% (n = 252) were former users and 18% (n = 166) were current users (with 31% using daily). Tobacco status was associated with HbA1c, BMI, self-care, distress, and blood glucose monitoring frequency. Across most outcomes, current users evidenced worse values relative to never users, and former users were largely similar to never users. Daily use was associated with significantly worse outcomes on HbA1c, diabetes self-care, and distress scores relative to less than daily use.

CONCLUSIONS

These cross-sectional comparisons suggest that current tobacco use is associated with worse status on important clinical diabetes indicators. Former users did not evidence these deleterious associations. Findings point to potential diabetes-specific motivators that could inform tobacco cessation interventions.

Cigarette smoking may accelerate the progression of IgA nephropathy

Background

Whether cigarette smoking is associated with the progression of immunoglobulin A nephropathy (IgAN) remains uncertain; therefore, we aimed to evaluate the effect of cigarette smoking on the prognosis of IgAN.

Methods

We divided 1239 IgAN patients from West China Hospital of Sichuan University who met the inclusion criteria into smoker (current or former) and non-smoker groups. The endpoint was end-stage renal disease (ESRD: eGFR < 15 mL/min/1.73 m² or undergoing renal replacement treatment) and/or eGFR decreased by > 50%. Kaplan–Meier, correlation, logistic regression and Cox proportional hazards analyses were performed. The association between cigarette smoking and IgAN was further verified by propensity-score-matched cohort analysis.

Results

During the mean follow-up period of 61 months, 19% (40/209) of the smoker group and 11% (110/1030) of the non-smoker group reached the study endpoint (p < 0.001). Multivariate Cox regression analysis revealed that cigarette smoking (hazard ratio (HR) = 1.58; p = 0.043) was an independent risk factor predicting poor renal progression in IgAN, and that IgAN patients with chronic kidney disease (CKD) stage 3–4 were more susceptible to cigarette smoking (p < 0.001). After propensity score matching (PSM), a significant correlation between cigarette smoking and renal outcomes in IgAN patients was seen. Furthermore, Spearman’s correlation test revealed that smoking dose was negatively correlated with eGFR (r = 0.141; p < 0.001) and positively related with proteinuria (r = 0.096; p = 0.001).

Conclusions

Cigarette smoking is an independent risk factor for IgAN progression, especially for advanced patients.

Diabetic nephropathy: A twisted thread to unravel

Diabetic nephropathy (DN), a persistent microvascular problem of diabetes mellitus is described as an elevated level of albumin excretion in urine and impaired renal activity. The morbidity and mortality of type-1 diabetics and type-2 diabetics due to end stage renal disease is also a result of the increased prevalence of DN. DN typically occurs as a consequence of an association among metabolic and hemodynamic variables, activating specific pathways leading to renal injury. According to current interventions, intensive glucose regulation decreases the threat of DN incidence and growth, and also suppressing the renin-angiotensin system (RAS) is a significant goal for hemodynamic and metabolism-related deformities in DN. However, the pathogenesis of DN is multifactorial so novel approaches other than glucose and blood pressure control are required for treatment. This review briefly summarizes the reported pathogenesis of DN, current interventions for its treatment, and possible novel interventions to unweave the thread of DN.

Nicotine, smoking, podocytes, and diabetic nephropathy

Diabetic nephropathy (DN) is the leading cause of end-stage kidney disease. Besides glycemic and blood pressure control, environmental factors such as cigarette smoking (CS) adversely affect the progression of DN. The effects of CS on DN progression have been attributed to combustion-generated molecules without consideration to the role of nicotine (NIC), responsible for the addictive properties of both CS and electronic cigarettes (ECs). Podocytes are essential to preserve the structure and function of the glomerular filtration barrier, and strong evidence indicates that early podocyte loss promotes DN progression. We performed experiments in human podocytes and in a mouse model of diabetes that develops nephropathy resembling human DN. We determined that NIC binding to podocytes in concentrations achieved with CS and ECs activated NADPH oxidase, which sets in motion a dysfunctional molecular network integrated by cyclooxygenase 2, known to induce podocyte injury; downregulation of AMP-activated protein kinase, important for maintaining cellular energy stores and antioxidation; and upregulation of CD36, which increased lipid uptake and promoted apoptosis. In diabetic mice, NIC increased proteinuria, a recognized marker of chronic kidney disease progression, accompanied by reduced glomerular podocyte synaptopodin, a crucial stabilizer of the podocyte cytoskeleton, and increased fibronectin expression. This novel study critically implicates NIC itself as a contributor to DN progression in CS and EC users.NEW & NOTEWORTHY In this study, we demonstrate that nicotine increases the production of reactive oxygen species, increases cyclooxygenase-2 expression, and upregulates Cd36 while inducing downregulation of AMP-activated protein kinase. In vivo nicotine increases proteinuria and fibronectin expression in diabetic mice. This study demonstrates that effects of nicotine on podocytes are responsible, at least in part, for the deleterious effects of smoking in the progression of chronic kidney disease, including diabetic nephropathy.

Renal resistive index in chronic kidney disease patients: Possible determinants and risk profile

BACKGROUND

High ultrasound renal resistive index (RI) predicts poor cardiorenal outcomes in chronic kidney disease (CKD) and has recently emerged as a marker of nephroprotective drugs response. Thus, having a risk profile of CKD patients with abnormal RI may be relevant for the clinicians.

METHODS

Consecutive patients referred to our non-dialysis CKD clinic from 01/01/2016 to 01/12/2016, were evaluated by clinical and ultrasound analysis. Inclusion criteria were age >18 years and presence of CKD defined as estimated glomerular filtration rate (eGFR)<60 mL/min/1.73m2 and/or proteinuria>0.150g/24h. Renal artery stenosis, solitary kidney, acute kidney injury were the main exclusion criteria. RI value was the mean of three measures in segmental arteries in each kidney. Univariate analysis was performed to evaluate associations between continuous RI and clinical variables. Multivariate linear regression analysis, based on stepwise method with an elimination criterion of p<0.10, was used to assess the independent correlates of RI as continuous variable.

RESULTS

We studied 73 patients (69.9% men). Mean RI was 0.67±0.09. Frequencies of diabetes and cardiovascular disease (CVD) were 19.2% and 20.6% and median eGFR 54.1 [30.0-84.6] mL/min/1.73m2. From low (<0.65) to intermediate (0.65-0.70) to high (>0.70) RI categories, eGFR and haemoglobin levels were decreased while diabetes, cardiovascular disease (CVD), phosphate and smokers were higher. At univariate analysis, RI was significantly associated with age, presence of diabetes, CVD, serum phosphorus, eGFR, Urea and haemoglobin. Multi-adjusted stepwise regression analysis showed that lower eGFR levels (p<0.001), diabetes (p = 0.042), CVD (p = 0.009), smoking habit (p = 0.021) and higher serum phosphorus levels (p = 0.001) were associated with higher continuous RI. Serum phosphorus showed Area Under the Curves (AUC) values of 0.714 and 0.664 for discriminating RI cut-offs of 0.70 and 0.65.

CONCLUSIONS

This analysis suggests that RI is higher in CKD patients with CVD, diabetes, smoking habit and higher serum phosphorus, regardless of eGFR. Further studies are needed to verify whether higher RI indicates more complex pathway of intrarenal damage, besides and beyond kidney function.

Cigarette smoke inhalation aggravates diabetic kidney injury in rats

Diabetic kidney disease (DKD) is the leading cause of end-stage kidney disease. Epidemiological studies have demonstrated that cigarette smoke or nicotine is a risk factor for the progression of chronic kidney injury. The present study analyzed the kidney toxicity of cigarette smoke in experimental rats with DKD. Experimental diabetes was induced in 7-week-old Sprague-Dawley rats by a single intraperitoneal injection of streptozotocin (60 mg kg^-1). Four weeks after the induction of diabetes, rats were exposed to cigarette smoke (200 μg L^-1), 4 h daily, and 5 days per week for 4 weeks. Cigarette smoke did not affect the levels of plasma glucose, hemoglobin A1c, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol or non-esterified fatty acids in both control and diabetic rats under the experimental conditions. Cigarette smoke, however, significantly increased diabetes-induced glomerular hypertrophy and urinary kidney injury molecule-1 (KIM-1) and neutrophil gelatinase-associated lipocalin (NGAL) excretion, suggesting exacerbation of diabetic kidney injury. Cigarette smoke promoted macrophage infiltration and fibrosis in the diabetic kidney. As expected, cigarette smoke increased oxidative stress in both control and diabetic rats. These data demonstrated that four weeks of exposure to cigarette smoke aggravated the progression of DKD in rats.

Association between Brachial-Ankle Pulse Wave Velocity and Microalbuminuria and to Predict the Risk for the Development of Microalbuminuria Using Brachial-Ankle Pulse Wave Velocity Measurement in Type 2 Diabetes Mellitus Patients

Brachial-ankle pulse wave velocity (baPWV) provides a useful means of assessing cardiovascular events and diabetic complications. However, the nature of associations between baPWV and microalbuminuria (MAU) and its presence in Type 2 diabetes mellitus (Type 2 DM) have rarely been investigated. This study aimed to examine the association between baPWV and MAU coupled with prediction of MAU using baPWV measurement among Type 2 DM patients. In this cross-sectional study, we enrolled 424 Type 2 DM patients who visited the cardiology and endocrinology department at a tertiary level health care facility, Republic of Korea between 1 January 2006 to 31 December 2008. Clinical and laboratory data were collected, and risk factors associated with MAU and prediction of risk for the development of MAU using baPWV measurement. The association between MAU and baPWV was examined using multivariable logistic regression analysis and predicted MAU by using receiver operating characteristic (ROC) curve analysis. Of the 424 Type 2 DM patients, 93 (21.9%) had MAU (20-200 μg/min). baPWV (cm/sec) was found to be significantly correlated with MAU levels (ug/min) (r = 0.791, p < 0.001). Further, baPWV was significantly associated MAU with higher odds ratio (adjusted odds ratio (AOR) 10.899; 95% confidence interval (CI) (4.518-26.292)). Similarly, smoking (AOR 10.899; 95% CI (4.518-26.292)), and low-density lipoprotein (LDL)-cholesterol (mg/dL) (AOR 1.017; 95% CI (1.001-1.033)) were also significantly associated with MAU. The appropriate cut-off value for baPWV to predict MAU 20 μg/min in our study was 1700 cm/sec (area under ROC curve = 0.976). This study shows that baPWV, cigarette smoking, and LDL-cholesterol are associated with MAU in Type 2 DM patients and suggests that a baPWV cut-off of 1700 cm/sec could be used to predict the presence of MAU (20 μg/min) in Type 2 DM patients in the Korean community.

Cigarette smoking as a risk factor for diabetic nephropathy: A systematic review and meta-analysis of prospective cohort studies

Background

Observational studies suggested that tobacco smoking was associated with diabetic nephropathy (DN). However, the results were conflicting and inconsistent. In the study, we performed a meta-analysis to assess the relationship between tobacco smoking and the development of DN.

Materials and methods

We searched in PubMed, Embase, Web of Science and the Cochrane Library (CENTRAL) from database inception until Mar 8, 2018, and updated our search on May 1, 2018. We screened the reference lists of the retrieved articles. Only original prospective cohort studies which have investigated the association between smoking and DN incidence or its progression were included. Pooled HRs and 95% confidence intervals (CIs) were calculated using a random effects model.

Results

A total of 9 prospective cohort studies were identified, including more than 203337 participants. Compared with those of no smoking, smoking participants increased the risk of developing DN (HR = 1.07, 95% CI: 1.01–1.13, P = 0.01). The subgroup analysis showed that the current and total smoking may increase the risk of DN, but these results did not reach statistical significance (current: HR = 1.69, 95% CI = 0.79–3.64, p = 0.17; total: HR = 1.17, 95% CI = 0.97–1.41, p = 0.10), whereas former smoking significantly increased the risk of DN (HR = 1.04, 95% CI = 1.03–1.05, p<0.001). Compared with no-smokers, smokers showed an elevated risk of developing DN (HR = 1.05; 95% CI, 1.00–1.11, P = 0.05). In patients with T2DM, those who smoked were at an increased risk of developing DN, as compared to those who had never smoked (HR = 1.05; 95% CI, 1.00–1.11, P = 0.05). However, compared to no smoking, smoking did not increase the risk of DN development in patients with T2DM (HR = 1.15; 95% CI, 0.9–1.47, P = 0.25). Univariate and multivariate meta-regression did not find any confounding factors. No publication bias was found in the meta-analysis.

Conclusions

The present study highlighted that smoking was an independent risk factor for DN, especially in patients with T1DM. This is the first meta-analysis of prospective cohort studies to discuss the relationship between smoking and DN.

Smoking and diabetes: dangerous liaisons and confusing relationships

The combined harmful effects of cigarette smoking and hyperglycemia can accelerate vascular damage in patients with diabetes who smoke, as is well known. Can smoking cause diabetes? What are the effects of smoking on macro and microvascular complications? Now growing evidence indicates that regular smokers are at risk of developing incident diabetes. Since the prevalence rates of smoking in patients with diabetes are relatively similar to those of the general population, it is essential to address the main modifiable risk factor of smoking to prevent the onset of diabetes and delay the development of its complications. Quitting smoking shows clear benefits in terms of reducing or slowing the risk of cardiovascular morbidity and mortality in people with diabetes. Does quitting smoking decrease the incidence of diabetes and its progression? What are the effects of quitting smoking on complications? The current evidence does not seem to unequivocally suggest a positive role for quitting in patients with diabetes. Quitting smoking has also been shown to have a negative impact on body weight, glycemic control and subsequent increased risk of new-onset diabetes. Moreover, its role on microvascular complications of the disease is unclear. What are the current smoking cessation treatments, and which ones are better for patients with diabetes? Stopping smoking may be of value for diabetes prevention and management of the disease and its macrovascular and microvascular complications. Unfortunately, achieving long-lasting abstinence is not easy and novel approaches for managing these patients are needed. This narrative review examines the evidence on the impact of smoking and smoking cessation in patients with diabetes and particularly in type 2 diabetes mellitus and its complications. In addition, management options and potential future directions will be discussed.

Association of kidney disease measures with risk of renal function worsening in patients with type 1 diabetes

BACKGROUND

Albuminuria has been classically considered a marker of kidney damage progression in diabetic patients and it is routinely assessed to monitor kidney function. However, the role of a mild GFR reduction on the development of stage ≥3 CKD has been less explored in type 1 diabetes mellitus (T1DM) patients. Aim of the present study was to evaluate the prognostic role of kidney disease measures, namely albuminuria and reduced GFR, on the development of stage ≥3 CKD in a large cohort of patients affected by T1DM.

METHODS

A total of 4284 patients affected by T1DM followed-up at 76 diabetes centers participating to the Italian Association of Clinical Diabetologists (Associazione Medici Diabetologi, AMD) initiative constitutes the study population. Urinary albumin excretion (ACR) and estimated GFR (eGFR) were retrieved and analyzed. The incidence of stage ≥3 CKD (eGFR < 60 mL/min/1.73 m2) or eGFR reduction > 30% from baseline was evaluated.

RESULTS

The mean estimated GFR was 98 ± 17 mL/min/1.73m² and the proportion of patients with albuminuria was 15.3% (n = 654) at baseline. About 8% (n = 337) of patients developed one of the two renal endpoints during the 4-year follow-up period. Age, albuminuria (micro or macro) and baseline eGFR < 90 ml/min/m² were independent risk factors for stage ≥3 CKD and renal function worsening. When compared to patients with eGFR > 90 ml/min/1.73m² and normoalbuminuria, those with albuminuria at baseline had a 1.69 greater risk of reaching stage 3 CKD, while patients with mild eGFR reduction (i.e. eGFR between 90 and 60 mL/min/1.73 m2) show a 3.81 greater risk that rose to 8.24 for those patients with albuminuria and mild eGFR reduction at baseline.

CONCLUSIONS

Albuminuria and eGFR reduction represent independent risk factors for incident stage ≥3 CKD in T1DM patients. The simultaneous occurrence of reduced eGFR and albuminuria have a synergistic effect on renal function worsening.

Dose-dependent effect of smoking on risk of coronary heart disease, heart failure and stroke in individuals with type 1 diabetes

AIMS/HYPOTHESIS

The aim of this study was to assess the potential dose-dependent effects of smoking on the risk of CHD, heart failure and stroke in individuals with type 1 diabetes.

METHODS

The study included 4506 individuals with type 1 diabetes who were participating in the Finnish Diabetic Nephropathy (FinnDiane) study. Intensity of smoking was estimated by packs per day and cumulative smoking by pack-years. Cox regression analyses were used to estimate the risk of incident CHD, heart failure or stroke during follow-up.

RESULTS

One pack per day significantly increased the risk of incident CHD in current smokers compared with never smokers (HR 1.45 [95% CI 1.15, 1.84]), after adjustment for age, sex, HbA_1c, hypertension, duration of diabetes and BMI. The risk of CHD in former smokers was similar to the risk in never smokers. The risk of incident heart failure was 1.43 (95% CI 1.03, 1.97) in current smokers per one pack per day and 1.37 (95% CI 1.05, 1.77) in former smokers, while the risk of incident stroke was 1.70 (95% CI 1.26, 2.29) and 1.49 (95% CI 1.14, 1.93), respectively. After further adjustments for lipids, however, the difference in the risk of heart failure in current and former smokers was no longer significant. Cumulative smoking data were similar to smoking intensity data.

CONCLUSIONS/INTERPRETATION

There is a dose-dependent association between smoking and cardiovascular disease in individuals with type 1 diabetes. In men in particular, the risk of incident stroke remains high even after smoking cessation and is increased in current and former smokers independently of other risk factors.

Interaction of MTHFR C677T polymorphism with smoking in susceptibility to diabetic nephropathy in Chinese men with type 2 diabetes

We investigated the interaction of MTHFR C677T polymorphism (rs1801133) with smoking in susceptibility to diabetic nephropathy (DN) in Chinese men with type 2 diabetes mellitus (T2DM). We studied 655 Chinese men with T2DM, who were divided into two groups (321 with DN and 334 without DN). The genotype of MTHFR C677T polymorphism was detected by real-time polymerase chain reaction. MTHFR TT genotype carried a higher risk of DN compared with the CC genotype (OR = 2.05; P = 0.002). The T allele showed marked association with DN development in patients who smoked, using additive, recessive, and dominant models (OR = 1.60, 1.83, and 1.88, respectively; P = 0.006, 0.002, and 0.04, respectively), which was not observed in the nonsmoking group. Patients with TT and CT genotypes, who smoked had a higher risk of DN compared with the control group (non-smoking with CC genotype; OR = 3.73 and 2.28, respectively; P < 0.001 and P = 0.004, respectively), whereas the other groups were not observed. In conclusion, the T allele of rs1801133 may be a risk factor for DN in Chinese men with T2DM, and synergy appears to exist between the MTHFR rs1801133 and smoking in susceptibility to DN.

Health-risk Behaviors and Type 1 Diabetes Outcomes in the Transition from Late Adolescence to Early Emerging Adulthood

This study examined within- and between-person associations between health-risk behaviors (smoking, drinking, insulin withholding) and type 1 diabetes (T1D) outcomes (adherence and HbA1c) during the high-risk transition from late adolescence to early emerging adulthood utilizing a 2-year longitudinal study. Beginning in the senior year of high school, participants (n = 197) with T1D completed measures of health-risk behaviors, adherence, and HbA1c annually at three time points. Health-risk behaviors were associated with poorer diabetes outcomes during the transition from late adolescence to early emerging adulthood. These results highlight the importance of monitoring health-risk behaviors regularly and intervening to reduce health-risk behaviors during this important developmental transition.

Prevention of Diabetic Kidney Disease in the Light of Current Literature

Diabetes is a rapidly growing problem of the community health. The resulting morbidity and mortality are responsible for the complications of diabetes. Nephropathy caused by diabetes often causes serious morbidity and mortality. In this review, we discuss the current approaches to prevent diabetic nephropathy based on the available literature evidence.

Smoking and the risk of diabetic nephropathy in patients with type 1 and type 2 diabetes: a meta-analysis of observational studies

Background

Conflicting evidence exists for observational studies on whether tobacco smoking is a risk factor for diabetic nephropathy (DN) in patients with type 1 (T1DM) and type 2 diabetes mellitus (T2DM). In this meta-analysis, we aimed to assess the effects of tobacco smoking on the development of DN.

Materials and Methods

We searched MEDLINE and EMBASE databases from their inception to March 31^st, 2017 for cross-sectional, case-control, and prospective cohort studies. We screened reference lists of retrieved articles. Summary relative risks (SRRs) and 95% confidence intervals (CIs) were calculated using a random-effects model.

Results

A total of nineteen observational studies (1 case-control, 8 cross-sectional and 10 prospective cohort studies) were identified, involving more than 78,000 participants and a total of 17,832 DN cases. Compared with never-smokers, there was an augmented SRR (95% CI) of DN in ever-smokers in patients with T1DM (1.31 [1.06–1.62]; P = 0.006) and T2DM (1.44 [1.24–1.67]; P < 0.001), respectively. In patients with T1DM, the SRR (95% CI) was 1.25 (0.86–1.83) for microalbuminuria only, 1.27 (1.10–1.48) for macroalbuminuria only, and 1.06 (0.97–1.15) for end-stage renal disease (ESRD). In patients with T2DM, the SRR (95% CI) associated with ever smoking was 1.46 (0.94–2.26) for microalbuminuria only, 1.72 (1.04–2.84) for macroalbuminuria only, and 1.10 (0.36–3.33) for ESRD.

Conclusions

Our meta-analysis suggests evidence for cigarette smoking as an independent risk factor for the development of DN in patients with both T1DM and T2DM.

Cigarette Smoking, Diabetes, and Diabetes Complications: Call for Urgent Action

PURPOSE OF REVIEW

This review aimed to examine the latest evidence linking cigarette smoking and cessation to risk of incident diabetes and its complications.

RECENT FINDINGS

Abundant evidence has demonstrated that smoking is associated with increased risk of type 2 diabetes and cardiovascular disease among diabetic patients, while its relationship with microvascular complications is more limited to diabetic nephropathy and neuropathy in type 1 diabetes. In addition, diabetes risk remains high in the short term after smoking cessation, while it reduces gradually in the long term. Risk of cardiovascular complications also substantially decreases after quitting smoking, but results for microvascular complications are not consistent. Smoking is associated with increased risks of incident diabetes in the general population and cardiovascular complications among diabetic patients. Although the short-term post-cessation diabetes risk needs to be acknowledged, this review calls for urgent action to implement population-wide policies and individual pharmaceutical and lifestyle interventions (if evidence accumulated in future) to aid smoking cessation and prevent diabetes and its complications.

Progress in Defining the Genetic Basis of Diabetic Complications

PURPOSE OF REVIEW

Diabetic complications affecting the kidneys, retina, nerves, and the cardiovasculature are the major causes of morbidity and mortality in diabetes. This paper aims to review the current understanding of the genetic basis of these complications, based on recent findings especially from genome-wide association studies.

RECENT FINDINGS

Variants in or near AFF3, RGMA-MCTP2, SP3-CDCA7, GLRA3, CNKSR3, and UMOD have reached genome-wide significance (p value <5 × 10^-8) for association with diabetic kidney disease, and recently, GRB2 was reported to be associated at genome-wide significance with diabetic retinopathy. While some loci affecting cardiovascular disease in the general population have been replicated in diabetes, GLUL affects the risk of cardiovascular disease specifically in diabetic subjects. Genetic findings are emerging for diabetic complications, although the studies remain relatively small compared to those for type 1 and type 2 diabetes. In addition to pinpointing specific loci, the studies also reveal biological information on correlated traits and pathways.

Predictors of chronic kidney disease in type 1 diabetes: a longitudinal study from the AMD Annals initiative

We evaluated 2,656 patients with type 1 diabetes mellitus and preserved renal function from the database of the Italian Association of Clinical Diabetologists network to identify clinical predictors for the development of chronic kidney disease. We measured estimated glomerular filtration rate (eGFR), urinary albumin excretion, HbA1c, lipids, blood pressure. Over a 5-year period 4.3% (n = 115) developed reduced eGFR (<60 ml/min/1.73 m²), 18.0% (n = 477) albuminuria, and 21.0% (n = 559) either one of the renal endpoints (CKD). Odds ratios for eGFR below 90 mL/min/1.73 m2 (1.48, P < 0.001), HbA1c (1.13, P = 0.002), triglycerides (1.04, P = 0.021 by 20 mg/dL), low density lipoprotein cholesterol (LDL-c) (0.95, P = 0.002 by 10 mg/dL) were independently related to the onset of CKD. Known duration of diabetes (1.15, P = 0.014 by 10 years), HbA1c (1.16, P = 0.001), triglycerides (1.05, P = 0.005 by 20 mg/dL), LDL-c (0.95, P = 0.003 by 10 mg/dL), antihypertensive treatment (2.28, P = 0.018) were related to the onset of albuminuria while age and presence of baseline eGFR values between 90 and 60 mL/min/1.73 m2, independently affected the developing of reduced eGFR (OR 1.95, P < 0.001 by 10 years and 2.92, P < 0.001). Patients with type 1 diabetes mellitus and unfavorable CV risk profile are at high risk of developing CKD. The two main traits of CKD share several determinants, although with some specificities.

Diabetic nephropathy: Time to withhold development and progression - A review

The recent discoveries in the fields of pathogenesis and management of diabetic nephropathy have revolutionized the knowledge about this disease. Little was added to the management of diabetic nephropathy after the introduction of renin angiotensin system blockers. The ineffective role of the renin- angiotensin system blockers in primary prevention of diabetic nephropathy in type 1 diabetes mellitus necessitated the search for other early therapeutic interventions that target alternative pathogenic mechanisms. Among the different classes of oral hypoglycemic agents, recent studies highlighted the distinguished mechanisms of sodium glucose transporter 2 blockers and dipeptidyl peptidase-4 inhibitors that settle their renoprotective actions beyond the hypoglycemic effects. The introduction of antioxidant and anti-inflammatory agents to this field had also added wealth of knowledge. However, many of these agents are still waiting well-designed clinical studies in order to prove their beneficial therapeutic role. The aim of this review of literature is to highlight the recent advances in understanding the pathogenesis, diagnosis, the established and the potential renoprotective therapeutic agents that would prevent the development or the progression of diabetic nephropathy.

The Genetic Landscape of Renal Complications in Type 1 Diabetes

Diabetes is the leading cause of ESRD. Despite evidence for a substantial heritability of diabetic kidney disease, efforts to identify genetic susceptibility variants have had limited success. We extended previous efforts in three dimensions, examining a more comprehensive set of genetic variants in larger numbers of subjects with type 1 diabetes characterized for a wider range of cross-sectional diabetic kidney disease phenotypes. In 2843 subjects, we estimated that the heritability of diabetic kidney disease was 35% (P=6.4×10^-3). Genome-wide association analysis and replication in 12,540 individuals identified no single variants reaching stringent levels of significance and, despite excellent power, provided little independent confirmation of previously published associated variants. Whole-exome sequencing in 997 subjects failed to identify any large-effect coding alleles of lower frequency influencing the risk of diabetic kidney disease. However, sets of alleles increasing body mass index (P=2.2×10^-5) and the risk of type 2 diabetes (P=6.1×10^-4) associated with the risk of diabetic kidney disease. We also found genome-wide genetic correlation between diabetic kidney disease and failure at smoking cessation (P=1.1×10^-4). Pathway analysis implicated ascorbate and aldarate metabolism (P=9.0×10^-6), and pentose and glucuronate interconversions (P=3.0×10^-6) in pathogenesis of diabetic kidney disease. These data provide further evidence for the role of genetic factors influencing diabetic kidney disease in those with type 1 diabetes and highlight some key pathways that may be responsible. Altogether these results reveal important biology behind the major cause of kidney disease.

The Association Between Smoking Tobacco After a Diagnosis of Diabetes and the Prevalence of Diabetic Nephropathy in the Korean Male Population

Objectives:

Smoking is known to be associated with nephropathy in patients with diabetes. The distinct effects of smoking before and after diabetes has been diagnosed, however, are not well characterized. We evaluated the association of cigarette smoking before and after a diagnosis of diabetes with the presence of diabetic nephropathy.

Methods:

We analyzed data from the 2011-2013 editions of the Korea National Health and Nutrition Examination Survey. A total of 629 male patients diagnosed with diabetes were classified as non-smokers (90 patients), former smokers (225 patients), or continuing smokers (314 patients). A “former smoker” was a patient who smoked only before receiving his diagnosis of diabetes. A “continuing smoker” was a patient who smoked at any time after his diabetes had been diagnosed. Diabetic nephropathy was defined as the presence of albuminuria (spot urine albumin/creatinine ratio ≥30 mg/g) or low estimated glomerular filtration rate (<60 mL/min/1.73 m²). Multiple logistic regression models were used to assess the independent association after adjusting for age, duration of diabetes, hemoglobin A1c, body mass index, systolic blood pressure, medication for hypertension, and medication for dyslipidemia. Female patients were excluded from the study due to the small proportion of females in the survey who smoked.

Results:

Compared to non-smokers, continuing smokers had significantly higher odds ratio ([OR], 2.17; 95% confidence interval [CI], 1.23 to 3.83) of suffering from diabetic nephropathy. The corresponding OR (95% CI) for former smokers was 1.26 (0.70 to 2.29).

Conclusions:

Smoking after diagnosis of diabetes is significantly associated with the presence of diabetic nephropathy in the Korean male population.