The effect of smoking on peripheral arterial perfusion in participants living with type 2 diabetes mellitus in Malta

Abstract

Background: Peripheral arterial disease (PAD) is a systemic disease often referred to as a progressive atherosclerotic disease that impedes arterial perfusion to the lower extremities. It is strongly associated with cardiovascular and cerebrovascular ischaemic events affecting both the expectancy and quality of life. Although tobacco smoking and type 2 diabetes mellitus are two main risk factors of PAD, they are still highly prevalent in Malta. Aim: To investigate the effect of tobacco smoking on peripheral arterial perfusion in participants living with type 2 diabetes mellitus in Malta. Objectives: To compare and conclude whether there is a statistical significance in arterial perfusion of the lower limbs between smokers, past smokers and non smokers living with type 2 diabetes mellitus in Malta using validated non-invasive diagnostic tools available in the primary care setting. Design & Methods: A non-experimental quantitative research was utilised to investigate the effect of tobacco smoking on peripheral arterial perfusion in a cohort of 32 participants with type 2 diabetes mellitus; [Smokers (n=11), Past smokers (n=11) and Non smokers (n=10)]. Participants were aged ≥ 40 & ≤ 85 years old, not subject to any high-risk factor linked with PAD except for tobacco smoking, type 2 diabetes mellitus and controlled hyperlipidaemia. The 3 smoking categories were matched on age (years), body mass index (BMI, kg/m2), eGFR (estimated glomerular filtration rate, mL/min/1.73m2), packet years (packs of cigarettes smoked per day multiplied by the years of continued smoking), duration of diabetes mellitus (years) and HbA1c levels (glycated haemoglobin, %) utilising frequency distribution. PAD was clinically assessed utilising the Toe Brachial Pressure Index (TBPI) & a hand held Doppler as part of the Huntleigh® Dopplex Assist instrument. TBPI value of ≤0.7 was suggestive of PAD while >0.7 was considered normal. Results: One Way ANOVA test showed significant difference in the TBPI scores between current, past and non smokers living with type 2 diabetes mellitus (p<0.05) when combining both left and right limbs (n=64) due to insignificant difference between left and right TBPI means (p>0.05). Chi-Square test found no significant difference between Doppler waveforms and smoking status (p>0.05) in both left (n=32) and right (n=32) feet, however χ2 tests showed larger percentages of non smokers with triphasic and biphasic waveforms, larger percentages of current smokers with monophasic and biphasic waveforms and larger percentages of past smokers with monophasic waveforms. Conclusion: Results of this study are in line with the literature with a low TBPI score indicative of PAD. This study has highlighted the important effects of tobacco smoking on peripheral arterial perfusion in individuals living with type 2 diabetes mellitus while also shedding light on the importance of smoking cessation and early identification of PAD especially in asymptomatic subjects were the disease can progress unnoticeably leading to severe lower limb and cardiovascular implications.