Painful Diabetic Polyneuropathy Linked to Increased Nighttime Blood Pressure

Painful diabetic polyneuropathy (PDPN) is associated with a higher nighttime blood pressure, independent of pain-related comorbidities, according to a study published in Diabetes Care.

Researchers from Tor Vergata University in Rome examined 113 total diabetic patients: 34 had PDPN, 33 had painless diabetic polyneuropathy (DPN⁺), and 46 did not have diabetic polyneuropathy (DPN^-). The participants were observed using various questionnaires over the course of the study.

PDPN affects sleep, mood, and quality of life for patients who are affected. However, it is often undiagnosed and undertreated, Vincenza Spallone, MD, the study’s principal investigator, told Medscape.

The researchers reported that patients with PDPN had higher symptom and sign scores when compared to their DPN^- counterparts. However, both groups displayed similar scores on cardiovascular autonomic reflex tests (CARTs).

The researchers also noted that the PDPN group displayed less change in systolic and diastolic blood pressure overnight levels when compared to the DPN group. The data showed no differences among the painless DPN⁺ and DPN^- groups.

The absence of nighttime decrease in blood pressure — or, what the researchers termed “nondipping” — was seen in 7% of participants (8 patients), and was correlated with PDPN status and a higher CART score.

The research team found nondipping participants experienced short sleep duration, just like patients in the general population who are high risk for obstructive sleep apnea. Spallone said in an interview that this finding suggests that nocturnal pain acts as a stressor for PDPN patients.

Following this study, the researchers hoped to be able to build off the data for future research projects, including looking to find ways to effectively implement pain treatment to correct abnormal blood pressure findings. The researchers said they are also working to find whether there is a potential benefit to blood pressure from pain relief, and if it is direct or mediated through sleep and/or mood changes.