Resting metabolic rate and respiratory quotient in human longevity

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These articles compare "long-lived"(>100) to elderly (75 to 99) and adults (<50).

"In multivariate analysis, both RMR and Rq had FFM, WHR, but not body mass index as significant and independent determinants."

"The major finding of our study is that the long-lived female seems protected from a metabolic age-related decline compared with aged females. Despite the fact that in the whole group of subjects an age-related decline in RMR and Rq was found, the analysis restrained to long-lived subjects showed in this group RMR and Rq greater than that found in aged subjects. Such a difference might be explained by the changes in anthropometrics features because long-lived subjects had lower BMI, FFM, and WHR than aged subjects."

Resting metabolic rate and respiratory quotient in human longevity.

Rizzo MR - J Clin Endocrinol Metab - 01-JAN-2005; 90(1): 409-13

15483081 (PubMed)Journal of Clinical Endocrinology and Metabolism

Abstract:Significant changes in body composition, body fat distribution, and resting metabolic rate (RMR) occur with aging. Interestingly, studies on human longevity pointed out that long-lived subjects are less prone to the anthropometrics and metabolic derangement normally observed in the elderly. Indeed, the relationship between energy expenditure and longevity has been poorly investigated. Thus, energy expenditure parameters of 28 long-lived subjects were assessed and compared with those of 26 adults and 27 younger elderly. All subjects enrolled were female.In the whole population, RMR was negatively correlated with age (P < 0.05), waist to hip ratio (WHR) (P < 0.001), fat mass (P < 0.001), and percent body fat (P < 0.03); respiratory quotient (Rq) displayed an age-related decrease (P < 0.001) and was negatively correlated with WHR (P < 0.001) and fat-free mass (FFM) (P < 0.006). In multivariate analysis, both RMR and Rq had FFM, WHR, but not body mass index as significant and independent determinants. Splitting the whole study group into subgroups according to age, long-lived subjects had oxygen volume, carbon dioxide volume, and Rq significantly higher than aged subjects but lower than adult subjects. In addition, long-lived subjects had total volume of expired air and RMR greater than aged subjects but not different from ones found in adults. In long-lived subjects, Rq was negatively correlated with percent body fat (P < 0.02), plasma glucose (P < 0.05), free fatty acid (P < 0.05), and WHR (P < 0.05), whereas RMR was negatively correlated with WHR (P < 0.05). No significant associations of RMR and Rq with FFM were found. In conclusion, our data demonstrate that human longevity seems protected toward an age-related decline. It is likely that the lack of the anthropometrics derangement may preserve long-lived subjects from the age-related decrease in energy metabolism.

"Previous studies on human longevity [3] focused their attention on anthropometrics [3] and endocrine [14] [15] and metabolic [16] [17] [18] characteristics of long-lived subjects and pointed out that such a group of subjects are less prone to the anthropometrics and metabolic derangement normally observed in the elderly. In particular, human longevity has been shown to be associated with lower body fat and waist to hip ratio (WHR) and with preserved insulin action compared with aged subjects. Due to the impact that anthropometrics features have on energy expenditure, one would also expect that human longevity is also associated with different energy expenditure and respiratory quotient (Rq) than ones reported in the elderly.

Notwithstanding, the relationship between energy expenditure and longevity has been poorly investigated. To address such an aim, RMR and Rq were evaluated in human longevity and compared with those in adults and aged subjects."

14. Paolisso G, Ammendola S, Del Buono A, Gambardella A, Riondino M, Tagliamonte MR, Rizzo MR, Carella C, Varricchio M 1997 Serum levels of insulin like growth factor-1 (IGF-1) and IGF-binding protein 3 in healthy centenarians: relationship with plasma leptin and lipid concentration, insulin action and cognitive function. J Clin Endocrinol Metab 82:2204–2209

"Fat intake was lower in centenarians (48.1 ± 2.1 g/day) than those in adults (78.9 ± 3.5 g/day; P < 0.001) and aged subjects (63.5 ± 3.9 g/day; P < 0.01). In contrast, daily carbohydrate intake in centenarians (45 ± 8% equivalent to 46.4 ± 3.4 g/day) was not different from that in aged subjects (43 ± 4% equivalent to 76.2 ± 3.6 g/day) or adults (47 ± 4% equivalent to 88.6 ± 4.4 g/day) as the percentage of total energy intake, but was the lowest as an absolute value ( P < 0.01 for all comparisons)."

TABLE 2 -- Metabolic characteristics of the study groups

Adults <50 yr (n = 30)

P

Aged 75-99 yr (n = 30)

P

Centenians 100 yr (n = 19)

Triglycerides (mmol/L)

0.9 ± 0.4

<0.05

1.2 ± 0.3

<0.03

1.0 ± 0.5

FFA (mumol/L)

328 ± 77

<0.05

395 ± 78

<0.01

305 ± 71

Total cholesterol (mmol/L)

5.8 ± 0.8

5.7 ± 0.9

5.5 ± 0.8(215) (185-245)

LDL cholesterol (mmol/L)

3.8 ± 0.7

<0.05

4.6 ± 0.5

<0.01

3.0 ± 0.5(115)

HDL cholesterol (mmol/L)

1.8 ± 0.2

<0.01

0.9 ± 0.3

<0.01

1.8 ± 0.3(70)

WBGD (mumol/kg FFM·min)

34.6 ± 1.1

<0.01

22.4 ± 0.4

<0.01

38.1 ± 1.6

THE PLASMA insulin-like growth factor I (IGF-I) concentration has been shown to decline with advancing age [1] ,[2] , but also to be influenced by sex steroids [3] , nutritional status [4] , and liver function [5] . More than 80% of plasma IGF-I circulates bound to IGF-binding protein-3 (IGFBP-3) and forms a large 150-kDa complex that cannot leave the circulation [1] ; thus, only the unbound form of IGF-I is considered to be biologically active [6] .

{BUT: "All subjects were normotensive, were taking no medications, were not smokers, and had no evidence of metabolic or cardiovascular disease. ...Subjects with a family history of noninsulin-dependent diabetes mellitus, obesity [body mass index (BMI), >30], or hypertension were excluded from the study. No woman was taking hormone replacement therapy before or during the study. "}

15. tti S, Barbesino G, Caterugli P 1993 Complex alteration of thyroid function in healthy centenarians. J Clin Endocrinol Metab 77:1130–1134

16. Paolisso G, Tagliamonte MR, Rizzo MR, Manzella D, Gambardella A, Varricchio M 1998 Oxidative stress and advancing age: results in healthy centenarians. JAGS 46:833–838 17. Paolisso G, Gambardella A, Ammendola S, D'Amore A, Balbi V, Varricchio M, D'Onofrio F 1996 Glucose tolerance and insulin action in healthy centenarians. Am J Physiol 270:E890–E896 18. Paolisso G, Gambardella A, Ammendola S, Tagliamonte MR, Rizzo MR, Capurso A, Varricchio M 1997 Preserved antilipolytic insulin action is associated with a less atherogenic plasma lipid profile in healthy centenarians. J Am Geriatr Soc 45:1504–1509