The History of “Essential” Hypertension Has Much To Teach Us About ObesityWednesday, November 13, 2019
I spent the first 10 years of my professional life studying and treating hypertension. As a bit of a history buff, I dug out old books on hypertension and went back to reading papers on blood pressure that were written in the 20s and 30s. I also had numerous mentors, who were around well before the advent of modern diagnostics or pharmacotherapy. In retrospect, I believe that there is much we can learn from the history of hypertension.
In the early part of last century, as we learnt more about the physiology of blood pressure regulation, numerous forms of “secondary” hypertension were identified (e.g. renal artery stenosis, Conn’s Syndrome, pheochromocytoma, etc.). Although these were rare conditions, they taught us much about pathophysiology – but (to this day), most case of elevated blood pressure are still considered “essential”, meaning that they do not appear to have a defined cause (genetics and environment both play a big role but the details remain rather murky).
Although the link between elevated blood pressure, stroke, heart disease, and kidney failure were well-recognised, there were no good treatments. In fact, the history of medical and surgical treatment of hypertension during the first part of the 1900s was so dismal, that many were opposed to treating hypertension with anything other than a highly restricted low-salt diet. Prior to the 1950s, pharmacotherapy included drugs like sodium thiocyanate, barbiturates, bismuth, bromides, hexamethonium, hydralazine, or reserpine – drugs that were poorly tolerated and for which there was little evidence that they lowered mortality. In desperate cases, surgeons performed sympathectomies – a drastic and complex operation.
Given the dismal landscape of medication for hypertension, there were loud voices that challenged the whole concept of hypertension. After all, if there were no good treatments, would it not be best to leave the patients alone and perhaps just support them in other ways? There were prominent doctors who warned about the possible damage that lowering blood pressure could do (particularly to the elderly). Even those who supported treatment, suggested modest targets – 170/110 mmHh was deemed “not so bad”.
Then came the 50s. The first modern drug to be introduced was the oral-diuretic chlorothiazide. Then came, beta-blockers, ca-antagonists, ACE-inhibitors, ARBs, and renin blockers.
Now that effective medications were available, researchers could conduct long-term studies to prove that these medications were not only safe and effective in lowering blood pressure, but could actually drastically reduce the incidence of strokes, heart attacks, and kidney failure.
But even as these studies were ongoing, there were the “nay” sayers. People who pointed out that, given the dismal history of hypertension medications, these should have no place in the clinic. People, who, even if they conceded that the medications were more effective and safer that ever before, pointed out that there was not enough data to support their routine use. There were those, who warned against lowering blood pressure too far and those who decidedly did not consider elevated blood pressures in the elderly a worthwhile target. And of course, there continued to be those that felt that rather than trying to treat hypertension, we should focus all efforts on preventing it by declaring a war on salt.
How things have changed. Today, no doctor would think twice about prescribing anti-hypertensive medications to a patient with elevated blood pressure. No payer would refuse the coverage of anti-hypertensive medications. No medical student leaves medical school without training in hypertension management. In fact, the only excuse today for anyone walking around with elevated blood pressure is either that they have not been diagnosed or are not taking their medications as prescribed (of course there are still some patients for whom the existing treatments are not tolerated or do not work, but these are few and far between).
I still recall the debates at conferences (my first hypertension conference was the World Hypertension Conference in Kyoto in 1988) on whether or not hypertension is a disease or just a risk factor. I recall proponents suggesting that simply improving lifestyles (without lowering blood pressures) would be as useful if not better for patients than exposing them to life-long pharmacotherapy (after all essential hypertension is just a “lifestyle” disease). I remember arguments about definitions and targets, about diagnostic strategies and therapeutic pathways (e.g. is it better to increase the dose, switch, or add-on?).
Funnily enough, I am reliving much of this history with obesity. There are those who, given the dismal past of anti-obesity medications, are vehemently opposed to the very notion that anti-obesity medications will one-day have a place in clinical obesity management. There are those, who given the past failures with dietary approaches (not unlike the failure of low-salt diets to produce long-term blood pressure lowering in most people), are ready to abandon dietary approaches all together (at least in the context of weight loss). Indeed, there are those who continue to argue that obesity is not really a disease but simply a risk factor attributable largely to lifestyle “choices”.
It took about 100 years for us to get to hypertension management as it exists today. In obesity, I think the wheels are moving a lot faster, although to many living with this disease, movement may appear glacial. Remember, less than 30 years have passed since the discovery of leptin. Only now are we entering the “modern” era of anti-obesity medications.
Yes, the debates about definitions and targets and treatment plans will continue but I am confident that sooner or later, we will get to the point where helping patients manage their obesity will be as routine, free of bias or judgement, and accepted as helping patients manage their hypertension.