Current smoking status may be associated with overt albuminuria in female patients with type 1 diabetes mellitus: a cross-sectional study

The association between cigarette smoking and diabetic nephropathy in Chinese male patients

AIMS

To investigate the association between cigarette smoking and the clinicopathological features and renal prognosis of type 2 diabetic mellitus (T2DM) patients with diabetic nephropathy (DN).

METHODS

A total of 223 T2DM male patients with biopsy-proven DN who received follow-up for at least 1 year were recruited. The patients were divided into two groups based on smoking status: smoking group and non-smoking group. Clinicopathologic differences were analyzed between the two groups. In addition, smokers were divided into two groups of binary analysis based on smoking amounts and two groups of former smokers and current smokers, and subgroups analysis based on age and DR, respectively. The influence of smoking on estimated glomerular filtration rate (eGFR) was estimated using logistic regression analysis and Cox regression on renal outcomes. Renal outcomes were defined by progression to end-stage renal disease (ESRD) or doubling of serum creatinine (D-SCr) level.

RESULTS

Compared with nonsmokers, smoking patients had more moderate decline eGFR (p = 0.032) and tubular atrophy and interstitial fibrosis (p = 0.033). The adjusted logistic regression analysis suggested cigarette smoking was negatively associated with more severe decline eGFR (p = 0.015), especially for patients with DR (p = 0.010) and patients of age ≤ 50 years (p = 0.012) in the subgroup analysis. In the prognosis analysis, no obvious significant risk factor was shown about smoking. Interestingly, it was observed that former smokers had lower levels of plasma glucose and triglycerides than current smokers (both p < 0.05), while smokers with small smoking amounts had lower levels of triglycerides than those with large smoking amounts (p < 0.05).

CONCLUSION

Cigarette smoking patients with T2DM and DN had more moderate decline eGFR, especially for DN patients with DR, and milder IFTA lesions, although an obviously significant risk factor was not shown about smoking for DN.

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.

Plasma Lipoprotein-Associated Phospholipase A₂ Levels Correlated with the Cardio-Ankle Vascular Index in Long-Term Type 2 Diabetes Mellitus Patients

The circulating levels of lipoprotein-associated phospholipase A₂ (Lp-PLA₂) can be a simple, but practical and useful marker of cardiovascular disease (CVD). As limited studies are available in patients with diabetes mellitus (DM), further studies are needed to establish the clinical application of Lp-PLA₂ in DM practice. The present study investigated the correlation between Lp-PLA₂ and the cardio-ankle vascular index (CAVI), a recent marker of arterial stiffness, in DM patients according to their diabetes duration. Clinical data, including the plasma Lp-PLA₂ mass and CAVI values, were collected from CVD-free type 2 DM female patients (n = 65, mean age 62 years, mean hemoglobin A1c 7.0%). The Lp-PLA₂ level of patients with a diabetes duration of <10 years (n = 40:20.2 IU/mL) was not significantly different from that of patients with a diabetes duration of ≥10 years (n = 25:20.5 IU/mL), while the CAVI level was significantly higher in patients with ≥10 years (9.0) than in those with <10 years (8.1; p < 0.05). A stepwise multiple regression analysis found a positive correlation between the Lp-PLA₂ and CAVI levels (β = 0.43, p < 0.01) in patients with a diabetes duration of ≥10 years. This correlation between Lp-PLA₂ and CVAI suggests the possible use of Lp-PLA₂ in DM patients with long-term disease. Further studies on Lp-PLA₂ are warranted in DM practice in relation to the disease duration.

Incidence and Risk Factors Involved in the Development of Nephropathy in Patients with Type 1 Diabetes Mellitus: Follow Up Since Onset

OBJECTIVES

Estimation of the incidence of nephropathy as well as potential risk factors involved in its onset in a cohort of patients with type 1 diabetes who were followed from diagnosis.

METHODS

We studied 716 patients, who were followed for a mean (standard deviation [SD]) of 10.1 (SD: 5.3) years. We analyzed the influence of demographic characteristics and levels of glycated hemoglobin (A1C), lipids and blood pressure during the course of the disease by univariate and multivariate survival methods.

RESULTS

The cumulative incidence of nephropathy was 2.6%, 6.3% and 11.9% at 5, 10 and 15 years of evolution, respectively. The factors associated with increased risk for nephropathy were systolic blood pressure and A1C levels. An increment of 10 mm Hg in systolic blood pressure increases the risk by 36%, and an increment of 1% in A1C levels raises the risk by 13% at 5 years since onset and 68% at 10 years, and it doubles the risk at 15 years. Women have higher risk than men (hazard ratio 1.79; p=0.024).

CONCLUSIONS

Our study suggests that female gender and high levels of A1C and systolic blood pressure throughout the course of the disease are the main factors associated with an increased risk for development of nephropathy in patients with type 1 diabetes mellitus.