Network Age based on Heart Rate Variation Index

Table 2 in article below shows the range of HRV for age.  The index is the number between 1-99 reported as HRV. 

 I expect the number of the mean index per decade would correspond to the 50%.

Therefore one could relatively calculate a HRV index age roughly.

Table 2. Aging Effects on 24-h Heart Rate Variability and Heart Rate by Decade

Age (yr)	SDNN (ms)	SDANN (ms)	SDNN Index (ms)	rMSSD (ms)	pNN50 (%)	HR (beats/min)
10–19	176 ± 38	159 ± 35	81 ± 20	53 ± 17	25 ± 13	80 ± 10
20–29	153 ± 44	137 ± 43	72 ± 22	43 ± 19	18 ± 13	79 ± 10
30–39	143 ± 32a	130 ± 33	64 ± 15a	35 ± 11a	13 ± 9a	78 ± 7
40–49	132 ± 30a	116 ± 31a	60 ± 13ab	31 ± 11ab	10 ± 9a	78 ± 7
50–59	121 ± 27a	106 ± 27a	52 ± 15ab	25 ± 9ab	6 ± 6ab	76± 9
60–69	121 ± 32a	111 ± 31a	42 ± 13abcd	22 ± 6ab	4 ± 5ab	77 ± 9
70–79	124 ± 22a	114 ± 20a	43 ± 11abcd	24 ± 7ab	4 ± 5ab	72 ± 9
80–99	106 ± 23abc	95 ± 24abc	37 ± 12abcd

From the above an index score of 77 in a 35 year old corresponds to an 18 year old.

From the above an index score of 64 in a 62 year old corresponds to a 35 year old.

I conjecture that, like lung age, function follows the HRV index age for walking speed, working memory and balance in the aging individual because the brain network speed determines these parameters in other studies.

I further conjecture that network integrity and speed is determined by BDNF levels that protect synapticity, function and integrity of neurons at small scale and memory, mood and metabolism at a larger scale.

Prior studies show that increased IQ processing speed and working memory delays symptoms and signs of dementia.

Other studies show that advanced degrees and lifetime learning also delays symptoms and signs of dementia by building a larger, more robust network.

Dementia or network disconnection syndrome harms smaller and slower networks to levels of symptomatic degradation  sooner than larger or faster networks.

As dementia reflects loss of 2 or more cognitive domains (intelligence, memory, affect, judgement and orientation) and cognitive impairment affects only memory, these are simply later and earlier stages of disconnection syndrome respectfully.

http://www.sciencedirect.com/science/article/pii/S0735109797005548

Joseph Thomas (Tony) Liverman,