Interarm blood pressure differences in the women's interagency HIV study

The relation between inter arm blood pressure difference and presence of cardiovascular disease: a review of current findings

Raised inter arm blood pressure difference (IABPD) is already well-known as a clinical sign of peripheral arterial diseases including aortic dissection and subclavian stenosis. However, there are several other diseases associated with high IABPD. Therefore, this study aimed to review the association between increased IABPD and the presence of lethal health conditions, the possible mechanisms behind this relationship, and its contributing risk factors. Significant IABPD has been observed in patients with atherosclerotic plaques, peripheral artery disease, coronary artery disease, and chronic kidney disease. Patients with high IABPD are also at more risk of left ventricular hypertrophy that may affect long-term cardiac function. Besides, brain injuries such as stroke, dementia, and Alzheimer's disease has been related to increased IABPD. Considering that raised IABPD is associated with multiple cardiovascular diseases and other organ damage, IABPD detection may be accurate for the early diagnosis and screening of these life-threatening diseases and help manage them better.

Association between interarm blood pressure differences and diabetic retinopathy in patients with type 2 diabetes

BACKGROUND

The effect of interarm blood pressure difference on the development of diabetic retinopathy, proteinuria and chronic kidney disease remains unknown. We investigated to determine the impact of interarm blood pressure difference on the prevalence of diabetic retinopathy, proteinuria and chronic kidney disease in patients with type 2 diabetes.

METHODS

The study included 563 patients with diabetes, who were evaluated with a simultaneous bilateral blood pressure measurement. The cutoff values for interarm blood pressure difference were 5, 10 and 15 mmHg. Logistic regression analysis was used to explore the relation between interarm blood pressure difference and diabetic retinopathy, proteinuria and chronic kidney disease.

RESULTS

Diabetic patients with systolic interarm blood pressure difference ⩾5, ⩾10 and ⩾15 mmHg showed an increased risk of diabetic retinopathy [adjusted odds ratio = 1.48 (95% confidence interval = 1.01-2.18), odds ratio = 1.80 (95% confidence interval = 0.99-3.22), odds ratio = 2.29 (95% confidence interval = 1.00-5.23)] after adjustment. There were significant associations between interarm blood pressure difference ⩾5 and ⩾10 mmHg and proteinuria [odds ratio = 1.68 (95% confidence interval = 1.15-2.44), 1.89 (95% confidence interval = 1.05-3.37)].

CONCLUSION

The association between interarm blood pressure difference and the presence of diabetic retinopathy emerged even for systolic interarm blood pressure difference ⩾5 mmHg without interaction of systolic blood pressure. Systolic interarm blood pressure difference should be considered a surrogate marker for vascular complication in patients with type 2 diabetes.

Longitudinal association between adiposity and inter-arm blood pressure difference

This is the first longitudinal study evaluating whether adiposity is associated with inter-arm blood pressure difference. We evaluated 714 overweight/obese individuals aged 40-65 years over a 3-year follow-up. Systolic and diastolic blood pressures were measured in both arms simultaneously using an automated machine. Linear regression assessed the associations of body mass index, fat %, waist, neck, thigh, and arm circumferences (cm), with absolute inter-arm differences in systolic (IAS) and diastolic (IAD) blood pressure (mm Hg). Poisson regression was used for binary outcomes (IAS and IAD ≥ 10 mm Hg). All models were adjusted for age, gender, smoking, physical activity, and HOMA-IR. Adiposity measures were associated with increased IAS and IAD (β range: 0.09-0.20 and 0.09-0.30). Neck circumference showed the strongest association with IAS (β = 0.20, 95% CI: 0.03, 0.37) and IAD (β = 0.30, 95% CI: 0.12, 0.47); arm circumference showed a similar association with IAS, but lower with IAD. Highest quartiles of BMI, thigh, and arm showed significant associations with IAS (IRR: 2.21, 2.46 and 2.70). Highest quartiles of BMI, waist, neck, and arm circumferences were significantly associated with IAD (IRR: 2.38, 2.68, 4.50 and 2.24). If the associations are corroborated in other populations, adiposity may be an important modifiable risk factor for inter-arm blood pressure difference with a large potential public health impact.

Sources of inaccuracy in the measurement of adult patients' resting blood pressure in clinical settings: a systematic review

BACKGROUND

To interpret blood pressure (BP) data appropriately, healthcare providers need to be knowledgeable of the factors that can potentially impact the accuracy of BP measurement and contribute to variability between measurements.

METHODS

A systematic review of studies quantifying BP measurement inaccuracy. Medline and CINAHL databases were searched for empirical articles and systematic reviews published up to June 2015. Empirical articles were included if they reported a study that was relevant to the measurement of adult patients' resting BP at the upper arm in a clinical setting (e.g. ward or office); identified a specific source of inaccuracy; and quantified its effect. Reference lists and reviews were searched for additional articles.

RESULTS

A total of 328 empirical studies were included. They investigated 29 potential sources of inaccuracy, categorized as relating to the patient, device, procedure or observer. Significant directional effects were found for 27; however, for some, the effects were inconsistent in direction. Compared with true resting BP, significant effects of individual sources ranged from -23.6 to +33 mmHg SBP and -14 to +23 mmHg DBP.

CONCLUSION

A single BP value outside the expected range should be interpreted with caution and not taken as a definitive indicator of clinical deterioration. Where a measurement is abnormally high or low, further measurements should be taken and averaged. Wherever possible, BP values should be recorded graphically within ranges. This may reduce the impact of sources of inaccuracy and reduce the scope for misinterpretations based on small, likely erroneous or misleading, changes.

Blood pressure measurement method and inter-arm differences: a meta-analysis

BACKGROUND

Screening for inter-arm difference (IAD) of blood pressure (BP) at each first visit is recommended by numerous guidelines whereas it is unclear whether the method by which IAD is measured has significant influence on the IAD value.

METHODS

A systematic review is made of the studies reporting on double-arm measurements and the association of IAD with procedure characteristics (Medline/PubMed, Embase, and Cochrane Library).

RESULTS

The mean absolute IAD was 5.4 ± 1.7 and 3.6 ± 1.2 mm Hg for systolic and diastolic BP, respectively. Of all subjects 14% had a systolic IAD ≥10 mm Hg, 4% a systolic IAD ≥20 mm Hg, and 7% a diastolic IAD ≥10 mm Hg. The relative risk (RR) of obtaining a systolic IAD ≥10 and 20 mm Hg and a diastolic IAD ≥10 mm Hg is higher when measuring sequentially instead of simultaneously (2.2 (95% CI: 1.4-3.6), P < 0.01; 4.8 (95% CI: 1.1-21.9), P < 0.05 and 2.5 (95% CI: 1.0-6.3) P < 0.05, respectively), when using a manual instead of an automated device (2.1 (95% CI: 1.1-3.9), P < 0.05; 4.4 (95% CI: 1.8-10.8), P < 0.01 and 3.7 (95% CI: 1.6-8.6), P < 0.01, respectively) and when performing only one BP measurement instead of multiple (2.0 (95% CI: 1.1-3.8), P < 0.05; 4.3 (95% CI: 1.6-11.4), P < 0.01 and 4.4 (95% CI: 1.7-11.4), P < 0.01, respectively).

CONCLUSION

Screening for IAD of BP is important but the measurement methodology has a major influence on IAD results. To prevent overestimation and observer bias IAD should be assessed simultaneously at both arms, with one or two automatic devices and multiple readings should be taken.