Inter-Arm Blood Pressure Difference In Type 2 Diabetic Patients

Abstract

Background: Long standing metabolic derangement in diabetes mellitus(DM) is associated with functional and structural changes in many organs particularly the vascular system, where hyperglycaemia represents an independent risk factor for both small and large blood vessels diseases which lead to the clinical complications of diabetes^”1”. Poorly controlled type 2 DM is associated with microvascular, macrovascular, and neuropathic complications. Microvascular complications of DM include retinal, renal, and possibly neuropathic disease. Macrovascular complications include coronary artery and peripheral vascular disease^”4”. Blood pressure should be measured in both arms either in rapid succession or simultaneous- ly ; normally the blood pressure measurement should differ by less than 10 mmHg, independent of handedness. However, as many as 20% of healthy individuals have a blood pressure difference greater than 10 mmHg in the absence of symptoms or other examination findings. Blood pressure difference of >10mmHg can be associated with subclavian artery disease(atherosclerosis or inflammatory), supravalvular aortic stenosis, aortic coarctation, or aortic dissection^”6”.

Aim of study: To explore the association of type 2 diabetes mellitus and inter-arm difference of blood pressure.

Subjects and Methods:In this case-control study, 132 patients with type 2 DM were included to evaluate the inter-arm systolic and diastolic blood pressure difference and compare the results with that present in 132 healthy individuals as a control. In this study we excluded:1-All diabetic patients with a history of cardiovascular diseases like: ischemic heart disease, valvular heart diseases, heart failure, congenital heart diseases and others. 2-All diabetic patients with a history of cerebro-vascular diseases like ischaemic strokes and others. 3-Those with peripheral arterial diseases like intermittent claudication or ischemic limbs. 4-Those with a history of hypertension. In the both groups, different parameters were recorded including the patients age, sex, BMI, cigarettes smoking, s. lipid profile. In addition, duration of DM and HbA1c as an indicator of glycemic control were recorded in diabetic group. In both diabetic and control groups, inter-arm systolic and diastolic blood pressure differences were evaluated using the mercurial sphygmomanometer by the same doctor who checked the blood pressure in both arms in the same (sitting) positions for all diabetics and control groups.

Results and Discussion: In this study there was no significant association between the inter-arm blood pressure difference and most of the parameters that recorded including (age, sex, BMI, cigarettes smoking, duration of DM, s. lipid profile, and HbA1c).   Christopher E Clark et al. stated that a systolic inter-arm blood pressure difference ≥ 10 mmHg was observed in 10 % of patients with diabetes^”16”. In this study, I noticed that most of diabetics (44.7%) have IASBP difference less than 5 mmHg, 31.8% of them have IASBP difference in the range of (11-15mmHg), 14% of them have a difference in the range of (16-20 mmHg), and 4.5% have IASBP difference of ˃ 20 mmHg. While most of the control group (85.2%) have IASBP difference of less than 5 mmHg, and only 4.9% have a difference more than 10 mmHg. With significant correlation between diabetes and IASBP difference ( P.  value = 0.00001).  Regarding the IADBP difference, most of diabetics (84.8%) and most of control group (88.1%) have a difference of less than 5 mmHg, (6.8% of diabetics and 7.9% of control group) have a difference in the range of 6-10 mmHg, and only (8.4% of diabetics and 4% of control group) have IADBP difference of more than 10 mmHg. No significant association between diabetes and IADBP difference (P. value = 0.633).

Conclusion: There is a significant association between diabetes and inter-arm systolic blood pressure differen-ce. For this reason, all patients with DM should be checked for inter-arm blood pressure difference to avoid misdiagnosis of diabetics as normotensive depending on the arm with lower blood pressure reading, a problem that may expose the diabetic patient to further complications of hypertension in addition to that of diabetes.