IMO, Kaplan's BP Study is invalid

[Guest guest]

Hi All,

 

acubeach wrote:

> See: webmd.com/content/article/87/99574.htm

 

Norman Kaplan's study is not on Medline yet, so my comments

refer only to the data in the URL, above.

 

It said: " Researchers recruited middle-aged volunteers who had

normal BP or mild high BP. The average BP at baseline was

135/85 mmHg. The latest expert recommendations define high BP

as >/=140/90, while </=120/80 is is considered optimal. BPs

between 120-139/80-89 are now termed prehypertension, which

indicates the need for lifestyle interventions such as weight loss,

increased exercise, and limiting salt in the diet to lower BP before

it becomes hypertension " .

 

IMO, Kaplan is biased against AP in that he uses negative terms,

like " Acupuncture is heavily TOUTED to treat high BP ... "

[ www.healthcentral.com/PrintFormat/ PrintFullText.cfm?id=60854 ]

 

One cannot expect AP to lower BP significantly in NORMOtensive

subjects (subjects with normal BP). See: Guo & Ni (references).

 

By definition, a study of AP in NORMOtensive subjects is NOT a

study in HYPERtensive subjects! Therefore, from such a study, a

conclusion that AP cannot influence hypertension would be invalid.

 

The definition of what is a " NORMAL BP " range is debatable. BPs

normally are higher by day than by night. See recent Medline

abstracts at the end of this mail. In adults with no history of

hypertension, Hayashi et al classify Systolic/Diastolic BPs of 130-

139/85-89 mmHg as " high normal " .

 

As Kaplan's study group had a mean BP of 135/85 mmHg at

baseline, one can classify the group as NORMAL to HIGH-

NORMAL, therefore invalid for research on hypertension!

 

Best regards,

Phil

 

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REFERENCES

Guo W, Ni G. The effects of AP on BP in different patients. J Tradit

Chin Med. 2003 Mar;23(1):49-50. Zhenjiang Medical College,

Zhenjiang 212001, Jiangsu Province. 87 patients with different

types of diseases were treated with AP, and the changes of their

BP were investigated. The results showed that the total level of

systolic pressure in the 87 cases decreased (P < 0.05).

Especially, the systolic pressure in patients accompanied with

hypertension decreased significantly. It is suggested that when AP

is adopted to treat other diseases, it can decrease the systolic

pressure to a certain extent in patients accompanied with

hypertension, but it does not exert significant influence on both

systolic and diastolic pressure in patients with normal BP.

Publication Types: Case Reports PMID: 12747201 [PubMed -

indexed for MEDLINE]

 

Marczak BT, Paprocki A. [bP variability on the basis of 24-hour

ambulatory BP monitoring in a group of healthy persons - Article in

Polish] Przegl Lek. 2001;58(7-8):762-6. Oddzial Chorob

Wewnetrznych Wojewodzkiego Szpitala Podkarpackiego im. Jana

Pawla II w Krosnie. The aim of our research was to test 24-hour

variabilities of BP (BPV) in a group of healty persons. The group

consisted of 125 healthy persons (58 men and 67 women) 14-70

years old (mean age 33.8 +/- 14 years). Standard deviation (SD)

from average BP and the presence and size of night fall of arterial

BP (dippers and non dippers) was tested as parameters of BPLV.

Average twenty four hours systolic BP (SBP) in all the group was

119.7 +/- 10.9 mm Hg (123.5 +/- 11.5 mm Hg during the day and

106.2 +/- 12.2 at night). Average twenty-four-hour diastolic blood

pressure (DBP) in all group was 71.9 +/- 9.0 mm Hg (74.0 +/- 9.5

during the day, 62.8 +/- 9.3 mm Hg at night). The mean SD of 24-

hour SBP was 15.2 +/- 3.5 mm Hg (13.6 +/- for day's hours and

11.2 +/- 4.1 mm Hg at night). The mean SD of 24-hour DBP was

13.0 +/- 2.6 mm Hg (12.1 +/- 2.8 at the day and 9.8 +/- 3.0 at

night). There were no correlation between and SBP SD or DBP SD

and sex, age of the investigated patients and their membership to

dipper and nondipper group. The positive correlation between SBP

and and its SD was observed in the group with SBP below 120

mmHg and the same was ascertained in group of people below 40

years of life. Average night fall of SBP was 17.17 +/- 9.42 mm Hg

(13.9 +/- 7.4%). Average night fall of DBP was 11.70 +/- 6.91

mmHg (15.7 +/- 8.8%) Nondippers ascertained 28.8% of all group.

(32.8% of women and 24.4% of men). Multivariate analysis showed

relationship between membership to dipper group and mean diurnal

systolic BP (odds ratio 0.93, 95% confidence interval 0.89-0.97, p

= 0.02) and between low value of systolic pressure SD during all

day monitoring and mean diurnal systolic BP (odds ratio 0.94, 95%

confidence interval 0.89-0.99, p = 0.02). Variability of arterial blood

pressure is sex, age and mean diurnal pressure related.

Parameters of short and long term variability are characterised by

large repeatability. Our variability values can be voice in discussion

on the norms in analysis of normal BP patients. PMID: 11769383

[PubMed - indexed for MEDLINE]

 

Wizner B, Gryglewska B, Gasowski J, Kocemba J, Grodzicki T.

Normal BP values as perceived by normotensive and hypertensive

subjects. J Hum Hypertens. 2003 Feb;17(2):87-91. Department of

Internal Medicine and Gerontology, Jagiellonian University Medical

College, 10 Sniadeckich Street, 31-531 Krakow, Poland. In spite of

considerable progress, the control of hypertension in most

countries is still insufficient. One of the reasons may be the poor

awareness of the BP (BP) cutoff values that define hypertension.

The aim of this report is to verify the hypothesis that patients with

hypertension accept higher BP levels as normal. The study was

performed during a street-based BP screening project carried out

across Poland, in summer 1997. In 444 persons who voluntarily

participated in Cracow's part of the project, BP was taken on the

left arm, in the sitting position, after a minimum of 5 min of rest,

using a semiautomated device (Digital BP UA-702). A

questionnaire investigated participants' age, weight, height, level of

education, history of hypertension and perception of normal values

of BP. We compared measured BP values with those perceived as

normal, and with the values recommended by WHO/ISH guidelines

(<140/90 mmHg). To analyse the data we used Student's t-test and

linear regression with adjustment for age and body mass index

(BMI). Hypertensive subjects, compared with normotensives, were

less aware of normal BP values (47.4 vs 83.9%, P<0.001, for

systotic BP, and 77.4 vs 88.4%, P<0.01, for diastotic blood

pressure). Measured BP was positively related to BP values stated

as normal. A similar relation was observed for age and BMI. In

conclusion, poor awareness of normal BP values in hypertensives

can be an important factor hindering better BP control. Education

strategies might prove to be highly effective in helping to tackle the

epidemics of hypertension. PMID: 12574785 [PubMed - indexed for

MEDLINE]

 

Brown MA, Davis GK, McHugh L. The prevalence and clinical

significance of nocturnal hypertension in pregnancy. J Hypertens.

2001 Aug;19(8):1437-44. Department of Medicine, St George

Hospital, University of New South Wales, Kogarah, Sydney,

Australia. mbrown OBJECTIVE: To determine (a)

the prevalence of hypertension during sleep in pre-eclampsia and

gestational hypertension, and (b) whether women with hypertension

during sleep have worse pregnancy outcomes than hypertensive

pregnant women with controlled (normal) BP (BP) during sleep.

DESIGN: Prospective double-blind cohort study. SETTING:

Inpatients and outpatients managed in a day assessment unit

(DAU) at St George Hospital, Sydney, Australia. PARTICIPANTS:

A total of 186 hypertensive pregnant women, 158 of whom had

successful 24 h BP monitoring; 40% had proteinuric pre-eclampsia

(PE), 43% gestational hypertension (GH) and 17% essential

hypertension (EH). INTERVENTIONS: BP, 24 h non-invasive,

monitoring (Spacelabs 90207) was undertaken successfully in 158

women with PE, GH or EH, whether or not they were receiving

antihypertensives. Women and clinicians were blinded to results of

these BP monitors. Sleep hypertension was defined as BP >

117/68 mmHg at 26-30 weeks or > 123/72 mmHg after 30 weeks

gestation. MAIN OUTCOME MEASURES: Maternal and fetal

outcomes were compared between women with and without sleep

hypertension and the prevalence of sleep hypertension was

determined. RESULTS: Sleep hypertension was present in 59%,

more commonly in PE (79%) than GH/EH (45%), P < 0.0001.

Sleep hypertensives also had higher routine sphygmomanometer

BPs [137(10)/91(7) mmHg; mean(SD)] than women with normal

sleep BP [130(12)/ 87(8) mmHg] P = 0.007, and higher awake

ambulatory BP monitoring (ABPM) BPs [137(8)/88(7) versus

127(7)/79(6) mmHg], P < 0.0001. Awake, but not sleep, average

heart rate was lower in sleep hypertensives [85(11) versus 91 (10)

beats per minute, bpm], P = 0.002. Sleep hypertensives had a

significantly greater frequency of renal insufficiency, liver

dysfunction, thrombocytopenia and episodes of (awake) severe

hypertension (P < 0.05), as well as lower birth weight babies [2715

(808) versus 3224(598) g, P < 0.0001]. CONCLUSIONS:

Hypertension during sleep is a common finding in women with

hypertensive disorders of pregnancy, particularly pre-eclampsia.

These women also have higher awake BPs and a greater frequency

of adverse maternal and fetal outcomes. These findings are largely

explained by the greater likelihood of pre-eclamptics having sleep

hypertension. PMID: 11518852 [PubMed - indexed for MEDLINE]

 

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Best regards,

 

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it "

[Guest guest]

Does Kaplan or other researchers report on any consideration given to the

influence or effects of " ambulatory blood pressure monitors " on blood

pressure, or any other aspects of experimentation? (See Ted Kaptchuk's

article " Do medical devices have placebo effect? " )

 

This study reminds me of the recent bashing of Ginseng, based on supposed

evidence that is interferes with the action of warfarin (Coumadin) in

normal, young healthy subjects. Duh -- Ginseng is an adaptogen, and helps

such subjects maintain homeostasis in the presence of 'rat-poison'.

 

Some very good scientific work vis-a-vis ATx is beginning to appear. E.g.

the big British study published earlier this year, on migraine treatment.

Good in terms of comprehensively addressing a wide range issues of internal

and external validity. Kaptchuk et al also did a showcase preliminary

study of the use of magnets for knee pain, which focuses on methdological

thoroughness.

 

Good CAM / A/OM research is exercising the inherent aspect of Western

science that it continuously and self-critically refines it's own

methodology. We should push that to influence more refinement (and

intellectual honesty) in science in its own (WM) turf!