Ep 147: A 55-Year-Old with Hypertension
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This is Katarina Heidhausen, Executive Editor of Harrison's Principles of Internal Medicine. Harrison's Pod Class is brought to you by McGraw-Hills Access Medicine, the online medical resource that delivers the latest content from the best minds in medicine. And now, on to the episode. Hi, everyone. Welcome back to Harrison's Pod Class. We're your co-hosts. I'm Dr. Kathy Handy. And I'm Dr. Charlie Wiener, and we're joining you from the Johns Hopkins School of Medicine. Today's patient is a 55-year-old with hypertension.

Kathy, today's patient is a 55-year-old woman who was recently diagnosed with hypertension and started on medical therapy. She's very motivated and wants to discuss lifestyle modification to improve her prognosis. Let me just interrupt you there for a minute because the decision to treat hypertension has become a bit more complicated recently, so we should just review that quickly. What's new? Well, the decision-making for medical therapy has become more individualized and some of the thresholds and goals have changed.

Can you summarize them briefly for us? Well, the ACC and AHA guidelines now say that medical therapy should be considered for a patient with a systolic blood pressure of greater than 130 or a diastolic blood pressure of greater than 80 for secondary prevention in patients with known cardiovascular disease or for primary prevention in patients with at least a 10% 10-year risk of atherosclerotic disease.

The 130 systolic cutoff is a bit lower than in the past. Also, anyone with a systolic pressure greater than 140 or a diastolic pressure over 90 should be considered for medical therapy. We really should discuss medical therapy of hypertension in a future episode, but what about the role of lifestyle modifications? Are they instead of medical therapy or are they just modifiers of medical therapy?

That's a great question. Implementation of lifestyles that favorably affect blood pressure has implications for both the prevention and the treatment of hypertension.

Health-promoting lifestyle modifications are recommended for individuals with an elevated or at-risk blood pressure and also as an adjunct to drug therapy in people who already have a diagnosis of hypertension. The impact of lifestyle interventions on blood pressure is more pronounced in people with known hypertension. In short-term trials, some have been shown to prevent the development of hypertension.

In hypertensive individuals, even if these interventions do not produce a sufficient reduction in blood pressure to avoid drug therapy, the number of medications or doses required for blood pressure control may be reduced. Great. Well, that gets us to our question for today that asks, all the following lifestyle modifications have a positive effect on blood pressure except A, a diet high in fruits, vegetables, and low-fat dairy products. B, creatine supplementation.

C, reduction of alcohol consumption? D, reduction of dietary sodium? Or E, weight loss? The answer is B, creatine supplementation. So this is an over-the-counter supplement that many use to enhance muscle strength in conjunction with training. It has also been proposed as a candidate supplement for patients at risk of statin myopathy, but it will not lower blood pressure. Okay, well, what about the others? Let's talk a little bit about all the other ones that sound like they will work.

So let's start with weight loss because that's easy and not controversial. Prevention and treatment of obesity are important for reducing blood pressure and cardiovascular disease risk. In short-term trials, even modest weight loss can lead to a reduction of blood pressure and an increase in insulin sensitivity. In longitudinal studies, a direct correlation exists between change in weight and change in blood pressure over time.

Average blood pressure reductions of 6 mmHg systolic and about 3 mmHg diastolic have been observed with reduction in mean body weight by 15 to 20 pounds in overweight individuals.

So that's enough in some patients to be clinically relevant and potentially forestall medical therapy. What about exercise? That's never a bad idea, right? Hardly ever. Regular physical activity facilitates weight loss, it decreases blood pressure, and reduces the overall risk of cardiovascular disease.

Blood pressure may be lowered by 30 minutes of moderately intense physical activity, so something like brisk walking six to seven days a week, or by more intense, less frequent workouts. How about diet? Two of the options mentioned diets.

Let's start with sodium or salt. There is individual variability in the sensitivity of blood pressure to sodium chloride or salt, and this variability may have a genetic basis. Several genetic loci have been associated with salt sensitivity. Based on results of meta-analyses, lowering of blood pressure by limiting daily salt intake can lower blood pressure in hypertensive individuals and to a lesser extent in normotensive individuals.

and patients who are more salt sensitive may be most responsive to a diuretic. However, it's important to note that independent of its effect on blood pressure, excessive consumption of salt is associated with an increased risk of stroke and overall cardiovascular disease. I know there's a complex relationship between potassium, calcium, and sodium. We mentioned supplements before. Can those help?

Potassium supplementation has inconsistent, modest antihypertensive effects, but may be associated with reduced stroke mortality. Calcium supplementation also has an inconsistent and modest effect on blood pressure, particularly in patients who are normal calcemic. What about the diet that's specifically high in fruits, vegetables, and low-fat dairy products?

That's referring to the 1997 Dietary Approaches to Stop Hypertension, or the DASH trial, and subsequent work that's demonstrated that over an eight-week period, a diet high in fruits, vegetables, and low-fat dairy products lowers blood pressure in individuals with high normal blood pressures or mild hypertension. The initial randomized control trial aimed to maintain body weight and sodium intake to emphasize the effect of the diet.

Subsequently, it was demonstrated that lowering daily salt intake augmented the effect of this diet on blood pressure. This was one of a number of studies that have shown that diet can affect blood pressure independent even of weight loss. Okay, and our last lifestyle modification is reduction of alcohol consumption. I assume that's good too. Yeah, consuming three or more alcoholic drinks per day is associated with higher blood pressures and a reduction of alcohol consumption is associated with a reduction of blood pressure.

The teaching points of today's case are that the decision to treat hypertension should be individualized to your patient, taking into account their hemodynamics, their past medical history, and their cardiovascular risk. Lifestyle modifications such as weight loss, diet, reduced sodium intake, and limitation of alcohol consumption can have a salutary effect on blood pressure independent of concurrent medical therapy.

And you can find this question and other questions like it in the Harrison self-review book and online and read more about the topic in the Harrison's chapter on hypertension. Visit the show notes for links to helpful resources, including related chapters and review questions from Harrison's available exclusively on Access Medicine. If you enjoyed this episode, please leave us a review so we can reach more listeners just like you. Thanks so much for listening.