Smoking and diabetes risk: building a causal case with clinical implications

Assessment of Pre-existing Type 2 Diabetes Mellitus Prevalence and Risk Factors Among Colorectal Cancer Patients in King Abdulaziz Medical City, Jeddah

BACKGROUND

Diabetes mellitus (DM) and cancer are recognized as non-communicable chronic disorders which are among the top ten causes of death globally. In Saudi Arabia, the prevalence of type 2 DM (T2DM) and colorectal cancer (CRC) is alarmingly high. Both T2DM and CRC share common risk factors. In this study, we aim to assess the prevalence of pre-existing T2DM among CRC Saudi patients.

METHODS

In this cross-sectional study, data were collected from the medical records of 275 Saudi adult patients with CRC from 2009 to 2018 at King Abdulaziz Medical City, Jeddah (KAMC-J).

RESULTS

Participants had a mean age of 57.0 years, standard deviation (SD) of 13.0, and were mostly males (60.00%) and Saudi (100.0%). Participants had a mean BMI of 26.42 (7.35) kg/m². The prevalence of pre-existing T2DM in this study was 40.80%. 15.8% of participants were overweight and obese (BMI>30), respectively. The average age of diabetics and non-diabetics was 63.6 (10.64) and 52.73 (12.43), respectively. Diabetic patients are significantly older than non-diabetic patients (p<0.001). The average BMI for diabetics was 26.96 (7.26) kg/m², whereas the average BMI for non-diabetics was 25.93 (7.48) kg/m². No significant differences were found between the two groups.

CONCLUSION

This study provides new insight into the high prevalence of pre-existing T2DM in CRC patients in Saudi Arabia. In particular, the age of diagnosis of CRC in diabetic patients was significantly higher than in non-diabetics.

A Smartphone App (TRIANGLE) to Change Cardiometabolic Risk Behaviors in Women Following Gestational Diabetes Mellitus: Intervention Mapping Approach

BACKGROUND

Gestational diabetes mellitus (GDM) is the most common complication during pregnancy and is associated with an increased risk for the development of cardiometabolic diseases. Behavioral interventions can reduce this risk, but current solutions insufficiently address the requirements for such a program. The systematic development of a scalable mobile health (mHealth) promotion program for mothers during the first years post-GDM may contribute to solving this problem.

OBJECTIVE

The aim of this project was to systematically plan and develop a theory- and evidence-based mHealth intervention to change cardiometabolic risk behaviors in women during the first 5 years post-GDM that meets women's expected standards of commercial health apps.

METHODS

The intervention mapping steps 1 to 4 structured the systematic planning and development of the mHealth program described in this paper. Steps 1 and 2 led to a theory- and evidence-based logic model of change for cardiometabolic health. Based on this model, the prevention program was designed (step 3) and produced (step 4) in cooperation with industrial partners to ensure a high technological standard of the resulting smartphone app for the iPhone (Apple Inc). Step 4 included a user study with women during the first 5 years post-GDM once a beta version of the app ("TRIANGLE") was available. The user study comprised 2 test rounds of 1 week (n=5) and 4 weeks (n=6), respectively. The tests included validated questionnaires on user acceptance, user logs, and think-alouds with semistructured interviews.

RESULTS

The novel TRIANGLE app is among the first self-paced smartphone apps for individual habit change in the 3 lifestyle areas of physical activity, nutrition, and psychosocial well-being. The 3 core features-a challenge system, human coaching, and a library-address 11 behavioral determinants with 39 behavior change methods to support lifestyle changes. Participants in the user study showed a high acceptance, high perceived quality, and high perceived impact of the TRIANGLE app on their health behaviors. Participants tested the app regularly, used it intuitively, and suggested improvements. We then adapted the TRIANGLE app according to the insights from the user study before the full TRIANGLE program production.

CONCLUSIONS

The intervention mapping approach was feasible to plan and develop an innovative and scalable smartphone solution for women during the first 5 years post-GDM. The resulting TRIANGLE intervention has the potential to support behavior change for cardiometabolic disease prevention. However, the app needs further refinement and testing in clinical trials. Intervention mapping steps 5 (implementation plan) and 6 (evaluation plan) may support the integration of the TRIANGLE intervention into routine care.

TRIAL REGISTRATION

German Clinical Trials Register DRKS00012736; https://www.drks.de/DRKS00012736.

Risk Factors Associated With Diabetic Foot Ulcers and Its Relationship With ABI and Brachial-Ankle Pulse Wave Velocity

To evaluate the risk factors associated with diabetic foot ulcers (DFUs) and to analyze the relationship of DFUs and the value of Ankle-Brachial Index (ABI) and brachial-ankle pulse wave velocity (baPWV). In this retrospective study, the risk factors associated with DFUs were analyzed, and the value of ABI and baPWV were measured to find its relationship with DFUs. Binary logistic regression analysis indicated that neuropathy and ABI were independent risk factors for DFUs. The patients were divided into 2 groups according to the value of ABI. For patients with DFUs, the value of baPWV decreased with the decrease of ABI. In normal or high ABI group, about a quarter of patients who suffered from DFUs had a higher value of baPWV than the others without DFUs. The pathogenesis of DFUs was multifactorial. Regarding the occurrence and development of foot ulcers, the action of vascular occlusion was more important than vascular sclerosis. ABI measurements should be taken more seriously in patients with DFUs. baPWV should be taken with care in the follow-up of the patients without DFUs. However, in patients with a normal value of ABI, the degree of vascular sclerosis of patients with DFUs may be greater than those without ulceration.

Insulin restores the neurochemical effects of nicotine in the mesolimbic pathway of diabetic rats

This study examined whether insulin modulates the neurochemical effects of nicotine in the mesolimbic pathway of diabetic rats. The rats received vehicle or streptozotocin (STZ) to induce hypoinsulinemia. A subset of STZ-treated rats was implanted with insulin pellets that rapidly normalized glucose levels. Two-weeks later, dialysis probes were implanted into the nucleus accumbens (NAc) and ipsilateral ventral tegmental area (VTA). The next day, dialysate samples were collected during baseline and then following systemic administration of nicotine. Samples were also collected following intra-VTA administration of the gamma-aminobutyric acid (GABA)A receptor antagonist, bicuculline. Dopamine, GABA, glutamate, and acetylcholine (ACh) levels were assessed using liquid chromatography/mass spectrometry (LC/MS). The results revealed that vehicle-treated rats displayed a nicotine-induced increase in NAc dopamine levels. In contrast, STZ-treated rats did not display any changes in NAc dopamine following nicotine administration, an effect that was likely related to a concomitant increase in GABA and decrease in glutamate levels in both the NAc and VTA. Intra-VTA administration of bicuculline increased NAc dopamine in vehicle-treated rats, and this effect was absent in STZ-treated rats. Vehicle-treated rats displayed a nicotine-induced increase in ACh levels in the NAc (but not VTA), an effect that was lower in the NAc of STZ-treated rats. Insulin supplementation normalized the neurochemical effects of nicotine in the NAc and VTA of STZ-treated rats, suggesting that insulin modulates the neurochemical effects of nicotine in the mesolimbic pathway of diabetic rats.

Review of the role of cigarette smoking in diabetic foot

Diabetic foot ulceration has been a serious issue over the past decades in Asia, causing economic and social problems. Therefore, it is important to identify and reduce the risk factors of diabetic foot. Cigarette smoking has been reported to be associated with diabetes and its macrovascular complications, but the relationship between smoking and diabetic foot ulcers is still unclear. In the present review, we summarize the effects of cigarette smoking on diabetic foot ulcers with respect to peripheral neuropathy, vascular alterations and wound healing. One underlying mechanism of these impacts might be the smoking-induced oxidative stress inside the cells. At the end of this review, the current mainstream therapies for smoking cessation are also outlined. We believe that it is urgent for all diabetic patients to quit smoking so as to reduce their chances of developing foot ulcers and to improve the prognosis of diabetic foot ulcers.

Epidemiology and determinants of type 2 diabetes in south Asia

Type 2 diabetes has rapidly developed into a major public health problem in south Asia (defined here as Bangladesh, Bhutan, India, Nepal, Pakistan, and Sri Lanka) in recent decades. During this period, major lifestyle changes associated with economic transition, industrialisation, urbanisation, and globalisation have been key determinants in the increasing burden of non-communicable diseases. A decline in nutrition quality, reduced physical activity, and increased sedentary behaviours are reflected in the increasing prevalence of type 2 diabetes and related risk factors in the region. The International Diabetes Federation 2017 estimates of the prevalence of diabetes in adults in the region range from 4·0% in Nepal to 8·8% in India. The prevalence of overweight ranges from 16·7% in Nepal to 26·1% in Sri Lanka, and the prevalence of obesity ranges from 2·9% in Nepal to 6·8% in Sri Lanka. An increasing proportion of children, adolescents, and women are overweight or obese, leading to a heightened risk of type 2 diabetes. Ethnic south Asians present with greater metabolic risk at lower levels of BMI compared with other ethnic groups (referred to as the south Asian phenotype), with type 2 diabetes often developing at a younger age, and with rapid progression of diabetic complications. Because of the presence of multiple risk factors and a body composition conducive to the development of type 2 diabetes, south Asians should be aggressively targeted for prevention. In this Series paper, we detail trends in the prevalence of diabetes in the region and address major determinants of the disease in the context of nutrition and physical activity transitions and the south Asian phenotype.

Insulin dependent and independent normalization of blood glucose levels reduces the enhanced rewarding effects of nicotine in a rodent model of diabetes

The rewarding effects of nicotine have been previously shown to be enhanced in rodent models of diabetes. It is presently unclear whether the enhanced nicotine reward observed in the diabetes models are mediated via an insulin or glucose mechanism. This study examined whether the enhanced rewarding effects of nicotine observed in streptozotocin (STZ)-treated rats are insulin-mediated. Male and female rats were treated with STZ and the rewarding effects of nicotine (0.2 mg/kg) were measured using the conditioned place preference (CPP) procedure. Some STZ-treated animals received insulin supplementation via subcutaneous pellets immediately after STZ administration, while other rats received daily injections of dapagliflozin (10 mg/kg), a sodium-glucose cotransporter-2 inhibitor. Both male and female STZ-treated rats displayed hyperglycemia, and their blood glucose levels (BGLs) were normalized to control levels following insulin supplementation or dapagliflozin administration. STZ-treated male rats displayed higher nicotine CPP relative to vehicle-treated controls. This effect was abolished in rats that received insulin supplementation or dapagliflozin administration. STZ-treated female rats displayed reduced levels of nicotine CPP as compared to male rats, regardless of treatment condition. These results suggest that glucose plays a major role in modulating the rewarding effects of nicotine in male rats treated with STZ.

Lifestyle recommendations for the prevention and management of metabolic syndrome: an international panel recommendation

The importance of metabolic syndrome (MetS) lies in its associated risk of cardiovascular disease and type 2 diabetes, as well as other harmful conditions such as nonalcoholic fatty liver disease. In this report, the available scientific evidence on the associations between lifestyle changes and MetS and its components is reviewed to derive recommendations for MetS prevention and management. Weight loss through an energy-restricted diet together with increased energy expenditure through physical activity contribute to the prevention and treatment of MetS. A Mediterranean-type diet, with or without energy restriction, is an effective treatment component. This dietary pattern should be built upon an increased intake of unsaturated fat, primarily from olive oil, and emphasize the consumption of legumes, cereals (whole grains), fruits, vegetables, nuts, fish, and low-fat dairy products, as well as moderate consumption of alcohol. Other dietary patterns (Dietary Approaches to Stop Hypertension, new Nordic, and vegetarian diets) have also been proposed as alternatives for preventing MetS. Quitting smoking and reducing intake of sugar-sweetened beverages and meat and meat products are mandatory. Nevertheless, there are inconsistencies and gaps in the evidence, and additional research is needed to define the most appropriate therapies for MetS. In conclusion, a healthy lifestyle is critical to prevent or delay the onset of MetS in susceptible individuals and to prevent cardiovascular disease and type 2 diabetes in those with existing MetS. The recommendations provided in this article should help patients and clinicians understand and implement the most effective approaches for lifestyle change to prevent MetS and improve cardiometabolic health.

Type 2 diabetes is associated with an increased prevalence of respiratory symptoms as compared to the general population

Background

To estimate the prevalence of respiratory symptoms in individuals with type 2 diabetes, as compared to the general population.

Methods

Between 2007 and 2010 the screening questionnaire of GEIRD (Gene Environment Interactions in Respiratory Diseases) study was administered to two samples of Verona general population, aged respectively 45-64 years and 65-84 years, and to a convenience sample of individuals with type 2 diabetes, consequently recruited at the local Diabetes Centre. Ninety-four and 165 people with type 2 diabetes, aged respectively 45-64 and 65-84 years, were compared with 676 and 591 subjects in the same age range from the general population. The influence of type 2 diabetes on respiratory symptoms was evaluated by logistic regression models, controlling for sex, age (45-54, 55-64, 65-74, 75-84 years), education level, smoking habits and heavy vehicle traffic exposure and adjusting standard errors of ORs for intra-sample correlation.

Results

Compared to the general population, dyspnoea limiting walking pace on level ground (grade 2 dyspnoea) was more frequently reported by people with type 2 diabetes, irrespective of age (p < 0.001), while self-reported chronic cough/phlegm was more common in those aged 45-64 years (p = 0.02). These results were confirmed by multivariable analysis: compared to their counterparts from the general population, people with type 2 diabetes aged 45-54 years showed an increased risk of reporting grade 2 dyspnoea (OR = 3.92, 95% CI 3.28-4.68) or chronic cough/phlegm (OR = 1.69, 1.60-1.78). Similar figures held significant at older ages (75-84 years), although partially blunted (dyspnoea: OR = 1.79, 1.68-1.91; chough/phlegm: OR = 1.09, 1.03-1.16). As such, the interaction between age class and type 2 diabetes was significant for both respiratory disorders. The proportion of self-reported dyspnoea among individuals with type 2 diabetes significantly increased across incremental body-mass index (BMI), from 15.4 to 25.4% and further to 41.3% respectively in normoweight, overweight and obese patients (p = 0.048).

Conclusions

People with type 2 diabetes more frequently reported grade 2 dyspnoea and chronic cough/phlegm than the general population of the same age, although presenting similar smoking habits. Diabetes appears to anticipate the lung ageing process, recorded in the general population. The increased occurrence of dyspnoea at incremental BMI among individuals with type 2 diabetes may reflect both cardiovascular and respiratory impairment in this high-risk patient population.

Smoking and the risk of type 2 diabetes in Japan: A systematic review and meta-analysis

Cigarette smoking is the leading avoidable cause of disease burden. Observational studies have suggested an association between smoking and risk of type 2 diabetes mellitus (T2DM). We conducted a meta-analysis of prospective observational studies to investigate the association of smoking status, smoking intensity, and smoking cessation with the risk of T2DM in Japan, where the prevalence of smoking has been decreasing but remains high. We systematically searched MEDLINE and the Ichushi database to December 2015 and identified 22 eligible articles, representing 343,573 subjects and 16,383 patients with T2DM. We estimated pooled relative risks (RRs) using a random-effects model and conducted subgroup analyses by participant and study characteristics. Compared with nonsmoking, the pooled RR of T2DM was 1.38 (95% confidence interval [CI], 1.28–1.49) for current smoking (19 studies) and 1.19 (95% CI, 1.09–1.31) for former smoking (15 studies). These associations persisted in all subgroup and sensitivity analyses. We found a linear dose-response relationship between cigarette consumption and T2DM risk; the risk of T2DM increased by 16% for each increment of 10 cigarettes smoked per day. The risk of T2DM remained high among those who quit during the preceding 5 years but decreased steadily with increasing duration of cessation, reaching a risk level comparable to that of never smokers after 10 years of smoking cessation. We estimated that 18.8% of T2DM cases in men and 5.4% of T2DM cases in women were attributable to smoking. The present findings suggest that cigarette smoking is associated with an increased risk of T2DM, so tobacco control programs to reduce smoking could have a substantial effect to decrease the burden of T2DM in Japan.

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This meta-analysis examined smoking and diabetes risk among Japanese.

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Current and former smokers showed a higher risk of diabetes than non-smokers.

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Diabetes risk linearly increased with higher consumption of cigarettes.

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Diabetes risk steadily decreased after smoking cessation.