Clinical Briefs with Comments from Russell H. Greenfield, MD
Clinical Briefs
With Comments from Russell H. Greenfield, MD. Dr. Greenfield is Clinical Assistant Professor, School of Medicine, University of North Carolina, Chapel Hill, NC; and Visiting Assistant Professor, University of Arizona, College of Medicine, Tucson, AZ.
The Needle Points Down: Acupuncture and BP
Source: Flachskampf FA, et al. Randomized trial of acupuncture to lower blood pressure. Circulation. 2007;115:3121-3129.
Goal: To examine the potential blood-pressure modifying effects of acupuncture when offered by experts in traditional Chinese medicine.
Study Design: 6-week randomized, single-blind, controlled clinical trial.
Subjects: People aged 45-75 years with uncomplicated mild-to-moderate hypertension (140-170 / 90-109), untreated or on stable medical regimens, attending a general medical clinic in Germany (n = 160, with evaluable data on n = 133).
Methods: Subjects were recruited directly from a medical clinic, and subsequently underwent in-depth intake evaluations that included physical examination, blood pressure (BP) measurement in both arms, ECG, ambulatory and exercise BP determination, routine blood work, echocardiography, and renal ultrasonography. Those already taking antihypertensive agents were instructed to continue doing so. Subjects were randomized (stratified by medication status) to 6 weeks of either active or sham acupuncture, with treatment beginning within 2 weeks of randomization (total of twenty-two 30-minute sessions over 6 weeks). Participants were assigned to one of 4 different types of hypertension based on traditional Chinese medical criteria by a Chinese physician "unaware of randomization" and were fitted with an ambulatory blood pressure monitoring device that took 76 measurements a day (at 15-minute intervals during the day, 30-minute intervals at night). In the active group, needling points were chosen according to the type of hypertension, and the angle, depth, and method of needle manipulation conformed to typical prescriptions. Sham treatment consisted of an identical number, distribution, and duration of sessions, regardless of type of hypertension. Acupuncture was administered by one of 7 Chinese physicians trained and accredited at the Nanjing School of Traditional Chinese Medicine, all of whom had 5 years training in Chinese medicine, 5 years training in Western medicine, and several years practical experience, and none of whom spoke German. Subjects had 5 weekly sessions during the first 2 weeks, then 3 sessions weekly for the duration of the study. During each session, 3 acupuncture points were needled bilaterally (except for single points) for 20 minutes. At the end of the intervention period, subjects returned for 3 follow-up appointments: immediately post-treatment (within 3 days of last acupuncture session), 3 months, and 6 months after completing treatment. At each follow-up, BP was determined at rest, while ambulatory, and during exercise. Primary end points were average systolic and diastolic blood pressure (SDP and DBP, respectively), as determined by 24-hour ambulatory blood pressure monitoring. Secondary end points were mean daytime and nighttime SDP and DBP, and reduction in BP at peak stress during bicycle stress testing.
Results: Significant differences between the two groups were found for 24-hour SDP and DBP, daytime SDP and DBP, and nighttime SDP. Only a negligible change was identified regarding nighttime DBP. For the primary end points of 24-hour ambulatory SBP and DBP, the acupuncture group experienced a mean decrease of 5.4 and 3.0 mm Hg, respectively. The difference between acupuncture and sham acupuncture groups amounted to 6.4 mm Hg and 3.7 mm Hg for 24-hour SDP and DBP, respectively. The most pronounced distinction between the groups was for daytime SBP (7.3 mm Hg). The differences between results in the 2 groups were minimally impacted when subjects who did not complete the trial were included in the analysis, but the nighttime SDP change was rendered non-significant. All BP reductions seen in the active group disappeared at the 2nd and 3rd follow-ups. There was no significant impact from acupuncture on peak exercise BP.
Conclusion: Acupuncture, when applied according to principles of traditional Chinese medicine, but not sham acupuncture, lowers mean 24-hour ambulatory BP readings after 6 weeks of therapy.
Study strengths: Employed experts in Chinese medicine; stratification based on medication status; intention-to-treat analysis.
Study weaknesses: Single Chinese physician assigning types of hypertension; short trial duration; no controlling for physical activity, caffeine or salt intake; lack of generalizability (mostly young subjects with mild-to-moderate disease).
Of note: There was no financial incentive for participation, and no cost to subjects; exclusion criteria included diabetes and proteinuria; assignment of type of hypertension was based on bilingual questionnaire, physical examination, and further questioning with the aid of an interpreter; no subject was taking non-prescription medication or botanicals; 2 people in the active group found acupuncture painful and discontinued their participation; nighttime DBP was low in both groups at baseline; the most common complaint voiced by study participants was the demand on their time; most of the subjects were already on antihypertensive medication; a slight increase in BP parameters was noted in the sham acupuncture group.
We knew that: Arterial hypertension affects approximately 33% of adults in North America and Europe; in these same countries, the 1st and 3rd most common causes of death are myocardial infarction and stroke, two clinical entities whose incidence is increased in the setting of hypertension; pharmacologic treatment of elevated blood pressure is limited by side effects, cost, and patient compliance; lifestyle interventions to lower blood pressure are effective, but often difficult to maintain; the means by which acupuncture might lower BP remain speculative; ambulatory blood pressure monitoring appears to be prognostically superior to office blood pressure readings.
Comments: The authors of this interesting article promote the idea that acupuncture may be a valuable aid in the treatment of mild-to-moderate hypertension. While this is possible, such a conclusion is not a reasonable extension of the authors' findings. The problems are both readily apparent and daunting the need for multiple visits associated with likely significant costs, the level of training required by practitioners (would the same drop in blood pressure occur with Western medical acupuncture?), the moderate degree of blood pressure lowering, and the lack of clinical impact beyond the period of treatment. The findings of this trial are intriguing, and offer fodder for additional study, but they do not convince that acupuncture should be considered a therapeutic tool in the management of patients with elevated blood pressure.
What to do with this article: Remember that you read the abstract.
Mangia! Mediterranean Diet and Mortality
Source: Mitrou PN, et al. Mediterranean dietary pattern and prediction of all-cause mortality in a US population: Results from the NIH-AARP Diet and Health Study. Arch Intern Med 2007; 167:2461-2468.
Goal: To examine the association between a Mediterranean dietary pattern and cause-specific, as well as all-cause, mortality.
Study Design: Prospective cohort trial (data taken from the NIH-AARP Diet and Health Study).
Subjects: Members of AARP aged 50-71 years who responded to a questionnaire sent out in 1995-1996 and living in one of 6 states (CA, NC, FL, LA, NJ, PA), Detroit, or Atlanta (roughly 214,000 men and 166,000 women).
Methods: A total of 3.5 million questionnaires were sent out to members of AARP, with the final cohort comprising 380,296 subjects. Participants completed a 124-item food frequency questionnaire (FFQ) that was validated against two 24-hour recalls. Information about physical activity, hormone therapy, smoking, and demographics were also collected at baseline. Median, 25th, and 75th percentile of food group and micronutrient intakes were also determined at baseline. Conformity with the Mediterranean dietary pattern was assessed using the traditional Mediterranean diet score (tMed), which does include measures of dairy and total meat product intakes, but does not distinguish between total grains and whole grains, and the alternate Mediterranean diet score (aMed), which separates fruits and nuts into 2 groups, eliminates dairy, includes only whole grains, and only red and processed meat; follow-up was completed in 2005. Over the course of follow-up, a totals of 27,799 deaths were documented (vital status was corroborated using the Social Security Administration Death Master File.)
Results: Conformity with the Mediterranean diet in men was highest among those who were non-obese, physically active, married, currently not smoking, and who had a higher level of education. The same pattern held true for women, with the exception of marital status (higher conformity was also tied to current use of hormone therapy). Alcohol and total energy intakes were higher in men. Higher conformity with the Mediterranean dietary pattern was associated with a statistically significant decrease in all-cause mortality, including death due to cardiovascular disease or stroke, for both men and women. When smokers were excluded from analyses, the associations between aMed and all-cause mortality remained significant. Subgroup analysis revealed a strong inverse relationship between all-cause mortality and adherence to a Mediterranean dietary pattern amongst smokers with a body mass index of 18.5-25.0; however, smoking was associated with decreased conformity to the diet.
Conclusion: High conformity with the Mediterranean dietary pattern is associated with lower all-cause and cause-specific mortality for both men and women.
Study strengths: Large size of cohort; results adjusted for potential confounding factors such as smoking, age, and total energy intake.
Study weaknesses: Potential bias (self-selected population responding to AARP questionnaire, use of FFQ).
Of note: Only results from aMed were presented because data from the two scores were similar, and aMed had been modified in this instance for use in a US population; prior to this paper, no prospective US research had been published on the Mediterranean dietary pattern and its relation to mortality; exclusion criteria included past medical history of cancer; diabetes or heart disease; both tMed and aMed score alcohol intake, but only tMed employs gender-based ranges; the beneficial impact of the Mediterranean diet may be due to effects on inflammation and oxidative stress.
We knew that: The Mediterranean diet has been associated with a decrease in overall mortality, both in small studies and the large European Prospective Investigation into Cancer and Nutrition (EPIC) cohort study that involved over 500,000 subjects in 10 European countries; higher alcohol intakes have been associated with a protective effect with respect to cardiovascular disease, but are also tied to an increased incidence of cancer; conformity with a Mediterranean-type diet is associated with low levels of oxidized LDL-C, high antioxidant capacity, and decreased levels of C-reactive protein, IL-6, fibrinogen, homocysteine and white blood cells.
Comments: The typical Mediterranean diet includes tasty items that are also often high in fat, but it's the type of fat that may hold one of the keys to the diet's health benefits. Data strongly suggest that partaking of a Mediterranean style diet provides a more balanced ratio of intake of omega-6 to omega-3 fatty acids, which may translate into reduced inflammation in the body. Additionally, such a diet provides monounsaturated fats and fiber in abundance. In many ways, the findings of this well-done study are not surprising at all, but serve to corroborate earlier data and support a general sense of what a healthy diet that cuts across socioeconomic strata can look like.
On the other hand, one bit of information stands out, that being the effect of a Mediterranean style diet on non-obese smokers. While eating in this way does not fully prevent the known consequences of regular exposure to tobacco smoke, a protective effect was identified. Practitioners may, thus, be able to emphasize the importance of adherence to a Mediterranean-type diet to patients who have not yet successfully quit smoking.
What to do with this article: Keep a hard copy in your file cabinet.
Walk the Walk: Pedometers and Health
Source: Bravata DM, et al. Using pedometers to increase physical activity and improve health: A systematic review. JAMA 2007;298:2296-2304.
Goal: To examine the relationship between pedometer use in outpatient adults with physical activity and health outcomes. In addition, to evaluate the association between pedometer use and changes in body weight, serum lipids, fasting serum glucose and insulin, blood pressure and, lastly, to determine if setting a daily step goal improves health outcomes.
Study Design: Systematic review.
Methods: Two investigators independently abstracted 4 categories of variables (interventions, participants, outcomes, and quality) from English-language data identified from 7 databases (MEDLINE, EMBASE, Sport Discus, PsychINFO, Cochrane Library, Thompson Scientific, and ERIC), bibliographies of retrieved articles and relevant conference proceedings. Primary analyses used immediate post-intervention results. Abstractors resolved discrepancies through repeated review and discussion. Data were pooled using random-effects calculations, and meta-regression was then performed.
Results: Twenty-six studies with a total of > 2,700 subjects met inclusion criteria (8 randomized controlled trials [RCTs] and 18 observational studies [6 of which were actually RCTs but used visible step counts in both study cohorts, so for the purposes of this review they were classified as observational trials]). The majority of studies came out of North America. There was a high degree of heterogeneity amongst trials but the quality of reporting was deemed good and there was little evidence of publication bias. The mean age of participants was 49 years (5 studies had participants whose mean age was > 60 years) and 85% were women. Most were white, normotensive, overweight, and relatively inactive at baseline. The mean duration of pedometer use was 18 weeks, 5 trials took place in the workplace, 23 included a step diary, and 17 included physical activity counseling (mean of 7 sessions). Only 3 studies included dietary counseling. Participant intervention completion rates averaged 80%, but in 9 trials 100% of subjects completed the full intervention. In the RCTs, where the active group was encouraged to view and record daily step counts while control group participants had their pedometer readings hidden from them, pedometer users who could monitor their daily steps significantly increased physical activity by more than 2,000 steps / day above that of matched controls, while in the observational trials pedometer usage increased total daily step count by 2,183 above baseline measurements. Overall, pedometer usage increased physical activity by 26.9% over baseline, and pooled data from all studies showed that pedometer users decreased body mass index by 0.38 (statistically homogeneous result, and not directly related to the increase in number of steps taken daily) and experienced a decrease in their systolic blood pressure of 3.8 mm Hg (statistically heterogeneous result, most notable in those with higher baseline blood pressure). Those studies that reported on LDL-C and serum glucose levels did not find statistically significant changes (but baseline values were nearly normal). A key predictor of increased physical activity was having a step goal (the 3 trials that did not include a step goal, such as 10,000 steps per day, had no significant improvement in physical activity amongst pedometer users, an outcome shared by those in trials that did not require a step diary).
Conclusion: Use of a pedometer is associated with significant increases in physical activity and significant decreases in both BMI and blood pressure.
Study strengths: Assessment of heterogeneity of studies; each individual study was removed from analysis to assess its effect on summary estimates.
Study weaknesses: Only English studies included in analysis; no data on children; limited generalizability (subjects were mostly younger women); no independent review to resolve discrepancies between authors; degree of heterogeneity between studies; many of the trials included 2 or more interventions; the bulk of included trials represent relatively small studies of short/moderate duration.
Of note: Pedometer usage has surged and recommendations to take at least 10,000 steps a day are widespread, but little data supporting effectiveness of these interventions exist; only 2 of the studies reviewed reported on the percentage of subjects who reached their step goals; having the intervention take place outside of the workplace also predicted an improvement in physical fitness; counseling and duration of activity did not predict an increased number of daily steps, nor did the type of pedometer used; workplace fitness programs have been criticized for only attracting relatively fit employees; the decreases in blood pressure noted in this review were independent of decreases in BMI.
We knew that: Pedometers are relatively inexpensive; the Department of Health and Human Services recommends "physical activity most days of the week for at least 30 minutes for adults," but over 50% of US adults do not get adequate physical activity, and approximately 25% are not engaged in any leisure time physical activity; 2,000 steps is equivalent to walking about 1 mile; reducing systolic blood pressure by 2 mm Hg is associated with a 10% reduction in stroke mortality and 7% decrease in mortality from cardiovascular disease during middle-age.
Comments: Systematic reviews often proclaim major findings, but after thorough review one finds that the conclusions drawn are not fully supported by the data at hand. In this particular paper, the findings are likewise weakened by flaws inherent to such methodology, but they are consistent across both RCTs and observational trials. The findings are good news in a day and age of rampant obesity, and knowing that blood pressure was found to drop independent of weight loss helps practitioners offer hope to patients who are trying but not yet succeeding in their weight management goals (fitness may improve even while body weight has not).
An important point emphasized by the authors is the need for a step goal. Subjects who could view their progress, and who documented their daily steps, experienced far greater benefits from using the pedometer. What the proper total step goal should be is yet to be determined, but setting a reasonable goal can help motivate people towards achieving an improved fitness level, and perhaps nudge them towards making healthier dietary choices or participating in other fitness activities. Known potential frailties of systematic reviews aside, this is an important paper.
What to do with this article: Make copies to hand out to your peers.
Greenfield RH. The Needle Points Down: Acupuncture and BP. 2008;11:32-34. Greenfield RH. Mangia! Mediterranean Diet and Mortality. 2008;11:34-35. Greenfield RH. Walk the Walk: Pedometers and Health. 2008;11:35-36.Subscribe Now for Access
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