Circulating ALT Levels in Healthy Volunteers Over Life-Span: Assessing Aging Paradox and Nutritional Implications

Figures & data

Figure 1. Weighted line for number of volunteers (n) at each year of age (21–84 years).

Figure 2. Age vs. average ALT for the given year (21–84 years). A weighted line is shown.

Figure 3. Year of age vs. average group ALT for (21–64 years). Positive correlation is depicted.

Figure 4. Year of age vs. average ALT (65–84 years). Negative correlation is depicted.

Figure 5. Year of age vs. average AST. Both weighted and linear correlation lines displayed.

Table 1. Correlation of aminotransferases (ALT, AST) at different ages of individual subjects.

Parameters	ALT	AST
All age (21–84 years)
r value	−0.01	0.05
n (count)	10,809	11,334
p value	0.44	< 0.001
Younger age (21–64 years)
r value	0.02	0.03
n (count)	9,196	9,680
p value	0.08	< 0.001
Older age (65–84 years)
r value	−0.10	−0.01
n (count)	1,613	1,654
p value	<0.001	0.67

Note. ALT = alanine aminotransferase; AST = aspartate aminotransferase.

Figure 6. Year of age vs. average FBG. A weighted line is shown.

Figure 7. Year of age vs. FBG for older (64–84 years). A negative linear correlation is depicted.

Table 2. Parameters showing aging paradox displayed in grey (age in years vs. dependent variable).

Dependent variable	r (20–84 years)	r (20–64 years)	r (65–84 years)
N	64	44	20
Insulin sensitivity
FBG (mg/dl)	.685***	.894***	−.519*
Body composition
Body weight (lbs)	−.719***	−.270#	−.803***
Fat mass (lbs)	−.261*	.451**	−.759***
FFM (lbs)	−.815***	−.820***	−.615**
BMD (g/cm)	−.948***	−.925***	−.786***
Cardiac dynamics
SBP (mm Hg)	.445***	.343*	−.023
DBP (mm Hg)	.236#	.303*	−.025
Heart rate (beats/min) .030	.110	−.193
Blood Chemistries
Triglyc (mg/dl)	.227#	.796***	−.573*
HDL Chol (mg/dl)	.840***	.842***	−.085
Total Chol (mg/dl)	.731***	.941***	−.671**
LDL Chol (mg/dl)	.530***	.891***	−.683**
AST (IU/l	.501***	.358*	.020
ALT (IU/l)	−.101	.419**	−.432# 2 reveals
hsCRP (Units)	−.684***	−.564***	−.154
WBC (103ml^3)	−.566***	−.700***	.224
Neutro (103ml^3)	−.554	−.662***	.328

Note. FBG = fasting blood glucose; BMD = bone mineral density; SBP = systolic blood pressure; DBP = diastolic blood pressure; FFM = fat free mass; Triglyc = triglycerides; HDL = high-density lipoprotein; LDL = low-density lipoprotein; Chol = cholesterol; ALT = alanine aminotransferase; AST = aspartate aminotransferase; hsCRP = highly sensitive C-reactive protein; WBC = white blood cells; Neutro = neutrophils.

# p > 0.05 < 0.1.

* p > 0.05.

** p < 0.01.

*** p < 0.001.

Table 3. Aminotransferases correlations with FBG at different ages of individual subjects.

Parameters	ALT	AST
All age (21–84 years)
r value	0.12	0.04
n (count)	10,801	11,325
p value	< 0.001	< 0.001
Younger age (21–64 years)
r value	0.12	0.04
n (count)	9,191	9,675
p value	< 0.001	< 0.001
Older age (65–84 years)
r value	0.11	0.02
n (count)	1,610	1,650
p values	< 0.001	0.38

Note. ALT = alanine aminotransferase; AST = aspartate aminotransferase; FBG = fasting blood glucose.

Table 4. Mean 24-hour plasma glucose concentration (mg/dl).

Age (Months)	n ad libitum	n food-restricted
3–7	21 136 ± 2	21 119 ± 2
9–13	21 147 ± 2	21 126 ± 2
15–19	21 149 ± 2	21 131 ± 2
21–25	15 148 ± 3	19 135 ± 3
27–31		13 127 ± 3

Mean ± SEM.

Data from Masoro EJ, McCarter RJM, Katz MS, McMahan CA: Dietary restriction alters characteristics of glucose fuel use. J Gerontology. 47:B202-B208, 1992.

Figure 8. Example of survivor bias. Average mean 24-hour glucose levels over the combined life-span of ad libitum fed and caloric-restricted male F344 rats. Figures in parentheses indicate number of rats surviving at that point. Data derived from Masoro EJ, McCarter RJM, Katz MS, McMahan CA: Dietary restriction alters characteristics of glucose fuel use. J Gerontology. 47:B202–B208, 1992.