Old, BMI, death risk

[Guest guest]

Elderly subjects are thought to require greater energy intakes to have less

weight

to be able to respond to the extra health risks of lower energy levels. The

below

paper appears to carefully analyze actual data with discerning criteria and find

the

opposite result. In the pdf-available below paper, the four comorbidities in

Table

4 may be:

" [1] functional status, falls, hospital admissions, weight loss, use of

medication, [2] reported chronic illness (hypertension, diabetes, chronic

obstructive pulmonary disease [COPD] and/or asthma, heart disease, and stroke),

[3]

lifestyle habits (physical activity, smoking history, and use of alcohol) and

[4]

socioeconomic status (education, housing, and monthly expenditure). "

Obesity, Physical Activity, and Mortality in a Prospective Chinese Elderly

Cohort

In This Issue of Archives of Internal Medicine

Arch Intern Med. 2006;166:1437. http://tinyurl.com/fevbe

... Obesity is usually associated with increased mortality in young and

middle-aged people. However, in older people, higher body mass index (BMI) ...

is

apparently protective ... A possible explanation for the observed relationship

between BMI and mortality in older people is reverse causality, because BMI in

this

age group is the result, not the cause, of underlying illness. In this case, BMI

in

older people would be a predictor of mortality as a marker of aging and health

status, and the association of BMI with mortality would be expected to differ

with

health status. In a prospective study of 54,088 older people, Schooling et al

showed

that the association between BMI and mortality varied with health status. In the

small minority (9%) of healthy older people who have never smoked, higher BMI

(>25)

was associated with higher mortality compared with normal BMI; however, in

unhealthy

older people, higher BMI was associated with lower mortality.

Obesity, Physical Activity, and Mortality in a Prospective Chinese Elderly

Cohort

C. Schooling; Tai Hing Lam; Zhi Bin Li; Sai Yin Ho; Wai Man Chan; Kin Sang

Ho;

May Ked Tham; J. Cowling; M. Leung

Arch Intern Med. 2006;166:1498-1504.

... a prospective cohort study of Chinese people 65 years or older enrolled

from 1998 to 2000 ... The effect of BMI on mortality varied with baseline health

status (P<.001). In the healthiest group, obese people (BMI 25) had higher

mortality

(adjusted hazard ratio

---

, 1.54; 95% confidence interval [CI], 1.02-2.33), but

in

the unhealthiest group they had lower mortality (HR, 0.55; 95% CI, 0.49-0.63)

compared with subjects of normal weight. Daily physical activity was associated

with

lower mortality compared with inactivity in the unhealthiest group (HR, 0.70;

95%

CI, 0.61- 0.81) but not in the healthiest group. ... In the elderly, the

relationship between obesity and mortality varies according to the underlying

health

status. In those with poor health status, obesity is associated with better

outcome,

whereas in those with initially good health status, obesity is associated with

worse

outcome.

Table 3. Risk for All-Cause and Cause-Specific Mortality by Body Mass Index and

Physical Activity of Elderly Health Center Clients in Hong Kong^*

============================================

Cause of death Deaths, no. Age at death, Mean (SD), y---BMI---Physical

activity

---<18.5 18.5-<23 =/>25 P^§---None </=30 m/d >30 m/d P^§

============================================

All causes 3819 78.7 (6.9)---1.78^§§ (1.61-1.97) 1.00 0.84^§§ (0.77-0.92)

0.75^§§

(0.70-0.82) <.001---1.00 0.83^§§ (0.76-0.91) 0.73^§§ (0.67-0.80) <.001

All causes at >2 y 2354 79.5 (6.74)---1.72^§ (1.51-1.97) 1.00 0.87^##

(0.78-0.97)

0.83^§§ (0.75-0.92) <.001---1.00 0.87^## (0.77-0.98) 0.77^§§ (0.69-0.87) <.001

Cancer 1503 77.1 (6.3)---1.60^§§ (1.35-1.91) 1.00 0.81^### (0.70-0.93)

0.82^###

(0.72-0.92) <.001---1.00 0.87 (0.75-1.01) 0.86^## (0.74-0.99) .06

Cardiovascular 1041 79.2 (6.6)---1.13 (0.90-1.42) 1.00 0.97 (0.83-1.14)

0.81^##

(0.70-0.94) .01---1.00 0.79^## (0.67-0.94) 0.63^§§ (0.53-0.74) <.001

Respiratory 563 81.1 (7.0)---3.71^§§ (3.02-4.54) 1.00 0.62^§§ (0.48-0.81)

0.52^§§

(0.41-0.66) <.001---1.00 0.84 (0.67-1.05) 0.66^### (0.53-0.84) <.001

Other and unknown 712 79.1 (7.1)---1.48^### (1.15-1.89) 1.00 0.86 (0.70-1.05)

0.70^## (0.58-0.84) <.001---1.00 0.82 (0.66-1.01) 0.70^### (0.57-0.86) .001

============================================

Abbreviation: BMI, body mass index (calculated as weight in kilograms divided

by

the square of height in meters).

^ *Unless otherwise indicated, data are reported hazard ratios (95%

confidence

intervals) mutually adjusted for age, sex, education, ever-drinking alcohol,

ever

smoking, monthly personal expenditure, housing and the other category (ie, BMI

or

physical activity).

^§ For linear trend.

^§§ P<.001.

^## P<.05.

^### P<.005.

Table 4. Risk for All-Cause Mortality by Body Mass Index and Physical Activity

of

Elderly Health Center Clients in Hong Kong^*

============================================

Comorbidities, no. Deaths, no.---BMI---Physical activity

---<18.5 18.5-<23 23-<25 =/>25 P^§---None </=30 min/d >30 min/d P^§

============================================

4-12 1481---1.76^** (1.51-2.07) 1.00 0.72^** (0.63-0.83) 0.55^** (0.49-0.63)

<.001---1.00 0.81^## (0.70-0.93) 0.70^** (0.61-0.81) <.001

3 894---1.81^** (1.45-2.26) 1.00 0.70^** (0.58-0.84) 0.64^** (0.55-0.75)

<.001---1.00 0.85 (0.70-1.03) 0.77^### (0.64-0.93) .01

2 864 2.22^** (1.81-2.73) 1.00 0.82^### (0.68-0.99) 0.72^** (0.61-0.85)

<.001---1.00 0.74^## (0.61-0.90) 0.70^** (0.58-0.84) .001

1 446---1.41^### (1.01-1.97) 1.00 1.04 (0.81-1.33) 0.98 (0.78-1.23)

..68---1.00

0.92 (0.70-1.21) 0.83 (0.63-1.08) .14

0 134---1.76^### (1.00-3.08) 1.00 0.96 (0.58-1.59) 1.54^### (1.02-2.33)

..16---1.00 1.24 (0.71-2.19) 1.15 (0.66-1.99) .83

============================================

Abbreviation: BMI, body mass index (calculated as weight in kilograms divided

by

the square of height in meters).

^* Unless otherwise indicated, data are reported hazard ratios (95%

confidence

intervals) mutually adjusted for age, sex, education, ever drinking alcohol,

ever

smoking, monthly personal expenditure, housing and the other category (ie, BMI

or

physical activity).

^§ For linear trend.

^** <.001.

^*** <.005.

^### <.05.

-- Al Pater, alpater@...

__________________________________________________

[Guest guest]

Hi folks:

This study Al has posted looks to me to be enormously significant.

In case anyone failed to notice what seems to be the key paragraph,

here it is:

" ..... (among) people 65 years or older ... in the healthiest group,

obese people (BMI 25) had higher mortality (adjusted hazard ratio

---

, 1.54; 95% confidence interval [CI], 1.02-2.33), but in the

unhealthiest group they had lower mortality (HR, 0.55; 95% CI, 0.49-

0.63) compared with subjects of normal weight " .

And ........

" Daily physical activity was associated with lower mortality compared

with inactivity in the unhealthiest group (HR, 0.70; 95% CI, 0.61-

0.81) but not in the healthiest group. ... "

So ........ the conclusion for us from this study seems to be that

if you are fundamentally healthy (as people on CRON should be) you

**DO** need a low BMI, and you **DO NOT** need daily physical

activity.

Presumably the logic behind the above associations is that in

fundamentally unhealthy people a low BMI may often result from

wasting caused by the underlying disease - the more the wasting (and

lower the BMI) the worse the disease, so a lower BMI indicates more

serious problems. However, as we know, a low BMI associated with

restriction of calories in fundamentally healthy people can extend

lifespan dramatically.

As for exercise, it may go some way to ameliorating the problems of

unhealthy people. But additional exercise is not required for

healthy people, because they do not have problems that need to be

ameliorated. (Not forgetting, as noted here many times, there is a

basic threshold level of exercise that is vital for preservation of

health for everyone. Bed-ridden people do not survive for long.)

Rodney.

>

> Elderly subjects are thought to require greater energy intakes to

have less weight

> to be able to respond to the extra health risks of lower energy

levels. The below

> paper appears to carefully analyze actual data with discerning

criteria and find the

> opposite result. In the pdf-available below paper, the four

comorbidities in Table

> 4 may be:

> " [1] functional status, falls, hospital admissions, weight

loss, use of

> medication, [2] reported chronic illness (hypertension, diabetes,

chronic

> obstructive pulmonary disease [COPD] and/or asthma, heart disease,

and stroke), [3]

> lifestyle habits (physical activity, smoking history, and use of

alcohol) and [4]

> socioeconomic status (education, housing, and monthly expenditure). "

>

> Obesity, Physical Activity, and Mortality in a Prospective Chinese

Elderly Cohort

> In This Issue of Archives of Internal Medicine

> Arch Intern Med. 2006;166:1437. http://tinyurl.com/fevbe

> ... Obesity is usually associated with increased mortality in

young and

> middle-aged people. However, in older people, higher body mass

index (BMI) ... is

> apparently protective ... A possible explanation for the observed

relationship

> between BMI and mortality in older people is reverse causality,

because BMI in this

> age group is the result, not the cause, of underlying illness. In

this case, BMI in

> older people would be a predictor of mortality as a marker of aging

and health

> status, and the association of BMI with mortality would be expected

to differ with

> health status. In a prospective study of 54,088 older people,

Schooling et al showed

> that the association between BMI and mortality varied with health

status. In the

> small minority (9%) of healthy older people who have never smoked,

higher BMI (>25)

> was associated with higher mortality compared with normal BMI;

however, in unhealthy

> older people, higher BMI was associated with lower mortality.

>

> Obesity, Physical Activity, and Mortality in a Prospective Chinese

Elderly Cohort

> C. Schooling; Tai Hing Lam; Zhi Bin Li; Sai Yin Ho; Wai Man

Chan; Kin Sang Ho;

> May Ked Tham; J. Cowling; M. Leung

> Arch Intern Med. 2006;166:1498-1504.

> ... a prospective cohort study of Chinese people 65 years or

older enrolled

> from 1998 to 2000 ... The effect of BMI on mortality varied with

baseline health

> status (P<.001). In the healthiest group, obese people (BMI 25) had

higher mortality

> (adjusted hazard ratio

---

, 1.54; 95% confidence interval [CI],

1.02-2.33), but in

> the unhealthiest group they had lower mortality (HR, 0.55; 95% CI,

0.49-0.63)

> compared with subjects of normal weight. Daily physical activity

was associated with

> lower mortality compared with inactivity in the unhealthiest group

(HR, 0.70; 95%

> CI, 0.61- 0.81) but not in the healthiest group. ... In the

elderly, the

> relationship between obesity and mortality varies according to the

underlying health

> status. In those with poor health status, obesity is associated

with better outcome,

> whereas in those with initially good health status, obesity is

associated with worse

> outcome.

>

> Table 3. Risk for All-Cause and Cause-Specific Mortality by Body

Mass Index and

> Physical Activity of Elderly Health Center Clients in Hong Kong^*

> ============================================

> Cause of death Deaths, no. Age at death, Mean (SD), y---BMI---

Physical activity

> ---<18.5 18.5-<23 =/>25 P^§---None </=30 m/d >30 m/d

P^§

> ============================================

> All causes 3819 78.7 (6.9)---1.78^§§ (1.61-1.97) 1.00 0.84^§§

(0.77-0.92) 0.75^§§

> (0.70-0.82) <.001---1.00 0.83^§§ (0.76-0.91) 0.73^§§ (0.67-0.80)

<.001

> All causes at >2 y 2354 79.5 (6.74)---1.72^§ (1.51-1.97) 1.00

0.87^## (0.78-0.97)

> 0.83^§§ (0.75-0.92) <.001---1.00 0.87^## (0.77-0.98) 0.77^§§ (0.69-

0.87) <.001

> Cancer 1503 77.1 (6.3)---1.60^§§ (1.35-1.91) 1.00 0.81^### (0.70-

0.93) 0.82^###

> (0.72-0.92) <.001---1.00 0.87 (0.75-1.01) 0.86^## (0.74-0.99) .06

> Cardiovascular 1041 79.2 (6.6)---1.13 (0.90-1.42) 1.00 0.97

(0.83-1.14) 0.81^##

> (0.70-0.94) .01---1.00 0.79^## (0.67-0.94) 0.63^§§ (0.53-0.74) <.001

> Respiratory 563 81.1 (7.0)---3.71^§§ (3.02-4.54) 1.00 0.62^§§

(0.48-0.81) 0.52^§§

> (0.41-0.66) <.001---1.00 0.84 (0.67-1.05) 0.66^### (0.53-0.84) <.001

> Other and unknown 712 79.1 (7.1)---1.48^### (1.15-1.89) 1.00

0.86 (0.70-1.05)

> 0.70^## (0.58-0.84) <.001---1.00 0.82 (0.66-1.01) 0.70^### (0.57-

0.86) .001

> ============================================

> Abbreviation: BMI, body mass index (calculated as weight in

kilograms divided by

> the square of height in meters).

> ^ *Unless otherwise indicated, data are reported hazard ratios

(95% confidence

> intervals) mutually adjusted for age, sex, education, ever-drinking

alcohol, ever

> smoking, monthly personal expenditure, housing and the other

category (ie, BMI or

> physical activity).

> ^§ For linear trend.

> ^§§ P<.001.

> ^## P<.05.

> ^### P<.005.

>

> Table 4. Risk for All-Cause Mortality by Body Mass Index and

Physical Activity of

> Elderly Health Center Clients in Hong Kong^*

> ============================================

> Comorbidities, no. Deaths, no.---BMI---Physical activity

> ---<18.5 18.5-<23 23-<25 =/>25 P^§---None </=30 min/d >30

min/d P^§

> ============================================

> 4-12 1481---1.76^** (1.51-2.07) 1.00 0.72^** (0.63-0.83) 0.55^**

(0.49-0.63)

> <.001---1.00 0.81^## (0.70-0.93) 0.70^** (0.61-0.81) <.001

> 3 894---1.81^** (1.45-2.26) 1.00 0.70^** (0.58-0.84) 0.64^**

(0.55-0.75)

> <.001---1.00 0.85 (0.70-1.03) 0.77^### (0.64-0.93) .01

> 2 864 2.22^** (1.81-2.73) 1.00 0.82^### (0.68-0.99) 0.72^**

(0.61-0.85)

> <.001---1.00 0.74^## (0.61-0.90) 0.70^** (0.58-0.84) .001

> 1 446---1.41^### (1.01-1.97) 1.00 1.04 (0.81-1.33) 0.98 (0.78-

1.23) .68---1.00

> 0.92 (0.70-1.21) 0.83 (0.63-1.08) .14

> 0 134---1.76^### (1.00-3.08) 1.00 0.96 (0.58-1.59) 1.54^###

(1.02-2.33)

> .16---1.00 1.24 (0.71-2.19) 1.15 (0.66-1.99) .83

> ============================================

> Abbreviation: BMI, body mass index (calculated as weight in

kilograms divided by

> the square of height in meters).

> ^* Unless otherwise indicated, data are reported hazard ratios

(95% confidence

> intervals) mutually adjusted for age, sex, education, ever drinking

alcohol, ever

> smoking, monthly personal expenditure, housing and the other

category (ie, BMI or

> physical activity).

> ^§ For linear trend.

> ^** <.001.

> ^*** <.005.

> ^### <.05.

>

> -- Al Pater, alpater@...

>

> __________________________________________________

>