Kai Wang ^1,2, Abraham A. Kroon ^1,2, Bastiaan E. de Galan ^1,2,3, Tos T.J.M. Berendschot ^4,5, Miranda T. Schram ^1,2,4,6, Alfons J.H.M. Houben ^*1,2, Marleen M. J. van Greevenbroek ^*1,2

1. Department of Internal Medicine, Maastricht University Medical Centre+ (MUMC+), Maastricht, The Netherlands. 2. Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, The Netherlands. 3. Department of Internal Medicine, Radboud University Medical Center, Nijmegen, The Netherlands. 4. School for Mental Health and Neuroscience (MHeNS), Maastricht University, Maastricht, The Netherlands. 5. Department of Ophthalmology, Maastricht University Medical Centre+ (MUMC+), Maastricht, The Netherlands. 6. Heart and Vascular Center, Maastricht University Medical Centre+ (MUMC+), Maastricht, The Netherlands. *Contributed equally. E-mail address of the presenting (first) author: k.wang@maastrichtuniversity.nl

Background

Hypertension and diabetes frequently coexist and may interact to induce diabetic microvascular dysfunction. We tested the hypothesis that persons with prediabetes or diabetes, have impaired retinal and glomerular autoregulatory responses to high blood pressure.

Methods

We used cross-sectional data from 6,594 participants (4,206 with normal glucose metabolism [NGM], 1,023 with prediabetes, and 1,365 with type 2 diabetes [oversampled]; mean age 59.8 ± 8.6 years; 50.2% men) of The Maastricht Study, a population-based cohort study. Using linear regression adjusted for cardiovascular and lifestyle risk factors, we tested if glucose metabolism status modified the associations of 24h systolic and diastolic blood pressure (SBP and DBP, independent variables, mmHg) with retinal arteriolar and venular diameters (CRAE and CRVE), and urinary albumin excretion (uAE) (dependent variables, standardized).

Results

The association of SBP with CRAE was attenuated by prediabetes (P_interaction =0.098) and diabetes (P_interaction <0.001) in females (but not males), with a beta of -0.21 SD per 10 mmHg (95% CI: -0.25, -0.16), -0.14 (-0.24, -0.05) and -0.04 (-0.14, 0.07) for NGM, prediabetes, and diabetes, respectively. The association of SBP with uAE was stronger in prediabetes (P_interaction =0.002) and diabetes (P_interaction <0.001) than in NGM, for the whole study population. The beta was 0.13 (0.11, 0.16), 0.20 (0.15, 0.26) and 0.24 (0.18, 0.29) for NGM, prediabetes and diabetes, respectively. Replacing SBP by DBP did not substantially change the results.

Discussion/Conclusion

Our findings suggest impaired retinal and glomerular autoregulatory responses to higher blood pressure in persons with (pre)diabetes, emphasizing the importance of blood pressure control in prediabetes and in diabetes care.