Postural changes in blood pressure among patients with diabetes attending a referral hospital in southwestern Uganda: a cross-sectional study

BACKGROUND: Orthostatic hypotension (OH) and orthostatic hypertension (OHT) are often unrecognized in clinical care for diabetic individuals, yet they are associated with increased risk for adverse cardiovascular outcomes. We aimed to determine the prevalence of the abnormal orthostatic blood pressure (BP) responses, and associated factors among diabetic individuals in ambulatory care for diabetes in southwestern Uganda. METHODS: We conducted a cross-sectional study among diabetic individuals aged 18–65 years at Mbarara Regional Referral Hospital, southwestern Uganda from November 2018 to April 2019. We obtained demographic and clinical data including a detailed medical history, and glycemic profile. BP measurements were taken in supine position and within 3 min of standing. We defined OH in participants with either ≥ 20 mmHg drop in systolic BP (SBP) or ≥ 10 mmHg drop in diastolic BP (DBP) after assuming an upright position. OHT was defined in participants with either a ≥ 20 mmHg rise in SBP, or ≥ 10 mmHg rise in DBP after assuming an upright position. Multivariate logistic regression was used to identify factors associated with OH and OHT. RESULTS: We enrolled 299 participants, with a mean age of 50 years (SD ± 9.8), and mean HbA1c of 9.7% (SD ± 2.6); 70% were female. Of the 299 participants, 52 (17.4%; 95% CI 13.3–22.2%) met the definition of OH and 43 (14.4%; 95% CI 10.6–18.9%) were classified as having OHT. In multivariable models, factors associated with diabetic OH were older age (OR = 2.40 for 51–65 years vs 18–50 years, 95% CI 1.02–5.67, P = 0.046), diabetic retinopathy (OR = 2.51; 95% CI 1.14–5.53, P = 0.022), higher resting SBP ≥ 140 mmHg (OR = 3.14; 95% CI 1.31–8.7.56, P = 0.011), and history of palpitations (OR = 2.31; 95% CI 1.08–4.92, P = 0.031). Self-report of palpitations (OR = 3.14; 95% CI 1.42–6.95, P = 0.005), and higher resting SBP ≥ 140 mmHg (OR = 22.01; 95% CI 1.10–4.42, P = 0.043) were associated with OHT. CONCLUSION: OH and OHT are common among diabetic individuals in ambulatory diabetes care in southwestern Uganda. Orthostatic BP measurements should be considered as part of routine physical examination to improve detection of OH and OHT, especially among older diabetics with complications of the disease. Future studies to assess the health and prognostic implications of OH and OHT among diabetics in the region are warranted.