Dr. Confounder

Finding holes in blood pressure research affecting patient care. Not medical advice. Not affiliated with any institution. @DrConfounder

Tag: bloodpressure

  • Major Headache

    Akavian I, Nitzan I, Twig G, Derazne E, Afek A, Cohen B, Calderon-Margalit R. Association Between Migraine and Hypertension in 2 Million Adolescents. Hypertension. 2025 Nov;82(11):e337-e345. doi: 10.1161/HYPERTENSIONAHA.125.24861. Epub 2025 Sep 4. PMID: 40904275.

    One of the best blood pressure readings I’ve ever had was taken for an insurance physical a couple of years ago. The nurse came to my house, and took my blood pressure with me sitting at the dining room table, left arm resting on the table, right arm petting the top of my soft fluffy doggy’s head. (Thanks buddy, you saved me money on insurance!)

    Now, imagine instead that I had been sitting in my doctor’s office suffering from a migraine, and they started by taking my blood pressure. How much higher would it have been? 30 points? 40? 50?

    The doctor explains that my blood pressure is high due to the shared microvascular pathology underlying my headache.

    No, you idiot, my blood pressure is high because I’m currently suffering with a damn headache.

    The doctor then tells me that I wouldn’t have this problem if I had received more intensive blood pressure control back in my twenties. In anger, my blood pressure goes even higher when rechecked 5 minutes later.

    This is the hypothesis suggested by a recent study in the journal Hypertension linking migraines to chronic hypertension. In this cross-sectional study of more than 2 million Israeli teenagers undergoing health screening for compulsory military service, subjects were screened for hypertension and were referred to a community physician if elevated pressures were detected. Migraines were diagnosed based on self-report. Overall patients with migraines had 3x the odds (adjusted) of hypertension, although overall only 0.2% received a hypertension diagnosis. More severe migraines were associated with higher blood pressures. (Obviously)

    In their discussion, the authors explain that prior studies on this issue were mixed, likely attributable to differences in population and methodology (i.e. were the patients being evaluated for military service at the times their blood pressures were checked?). They also address the contribution of stress, but claim to mitigate this by limiting the analysis to individuals without psychiatric conditions. As if headache pain would only raise blood pressure if you have bipolar disorder.

    At the end of the day, there very likely are complex microvascular phenomena contributing to both migraines and hypertension. But do we really think that a study involving a questionnaire and an air-filled plastic cuff is going to find them? And are the migraine patients flagged for high blood pressures actually the ones we need to worry about? Who knows?

    This gives me a headache.

  • An Unethical Research Proposal

    Wilson LM, Abebe KZ, Anderson TS. How Should Elevated Blood Pressure Be Managed in Hospital? NEJM Evid. 2024 Dec;3(12):EVIDtt2400202. doi: 10.1056/EVIDtt2400202. Epub 2024 Nov 26. PMID: 39589191.

    https://evidence.nejm.org/doi/full/10.1056/EVIDtt2400202

    Inpatient blood pressure management is an interesting topic, because while longitudinal outpatient studies have shown benefit from intensive blood pressure control (if deeply confounded), multiple inpatient studies have shown that any ad hoc blood pressure treatment in non-cardiac patients is associated with multifaceted harm (AKI, MI, stroke, mortality).

    In this “Tomorrow’s Trial” piece published in NEJM Evidence , the authors acknowledge this, but point to a lack of randomized trials to suggest that there may be a hidden benefit in terms of specifically reducing major adverse cardiac events, despite that observational studies have shown such blood pressure control to be associated with increased risk of MI (https://jamanetwork.com/journals/jamainternalmedicine/fullarticle/2774562) and stroke (https://www.ahajournals.org/doi/10.1161/HYPERTENSIONAHA.121.17279), with no threshold above which treatment has been shown to be beneficial.

    The authors go on to propose a trial where patients are randomized to one of two arbitrary blood pressure thresholds, 140mmHg or 160mmHg, despite the best evidence to date suggesting that patients in both groups would be at increased risk of harm.

    This violates the principle of equipoise or “genuine uncertainty” (https://www.ahajournals.org/doi/10.1161/circresaha.116.309594) as to the harm/benefit of the intervention. When observational studies predict harm in both arms, the lack of a randomized clinical trial for confirmation does not create clinical equipoise, making the proposed trial unethical.