Tag Archives: mortality

Quantifying Biological Age: Blood Test #3 in 2022

Join us on Patreon! https://www.patreon.com/MichaelLustgartenPhD

Levine’s Biological age calculator is embedded as an Excel file in this link from my website: https://michaellustgarten.com/2019/09/09/quantifying-biological-age/

An epigenetic biomarker of aging for lifespan and healthspan https://pubmed.ncbi.nlm.nih.gov/29676998/

Underlying features of epigenetic aging clocks in vivo and in vitro https://pubmed.ncbi.nlm.nih.gov/32930491/

Population Specific Biomarkers of Human Aging: A Big Data Study Using South Korean, Canadian, and Eastern European Patient Populations https://pubmed.ncbi.nlm.nih.gov/29340580/

Low Total Cholesterol: Biological Youth Or Increased Mortality Risk?

On my latest blood test (August 2015), my total cholesterol was 127 mg/dL-is that value optimal for health and longevity?

Based on data for 1,104,294 men younger than 60y (median age, 40y) that were followed for up to 14 years (Fulks et al. 2009), my 127 mg/dL value (1 – 2.4%) puts me relatively close to maximally reduced all-cause mortality risk, which occurs at 146-158 mg/dL (5-9% on the graph below):

c hdl mort

But what about the data for men older than 60?

In a 10-year study of 2,277 older adults (average age, ~77y), total cholesterol levels less than 175 mg/dL were associated with ~2-fold higher risk of all-cause mortality, compared with values greater than 226 mg/dL (Schupf et al. 2005):

tc less 175 acm

Similarly, in a 10-year study of even older adults (median age, 89y; 724 subjects), all-cause mortality risk was significantly increased in subjects with total cholesterol values less than 193 mg/dL (dark black line below), compared with values greater than 251 mg/dL (dashed line; Weverling-Rijnsburger et al. 1997). In addition, subjects with cholesterol values greater than 251 mg/dL lived ~2 years longer than those with values less than 191 mg/dL. So higher cholesterol in very old adults…increased lifespan! Does that mean I should alter my dietary approach to increase my circulating cholesterol levels after I reach 60?

chol 89y mort.png

To address that issue, it’s important to understand why cholesterol increases during aging. One possible mechanism involves the role of cholesterol in immune defense against infectious agents (bacteria, viruses, parasites, etc.). Obviously, our immune system is supposed to eliminate these pathogens, but immune function decreases with age (Targonski et al. 2007). As a compensatory mechanism, cholesterol can protect against infectious agents. For example, LDL cholesterol binds to and partially inactivates Staphylococcus aureus (Bhakdi et al. 1983). Staphylococcus aureus infection increases during aging, as its incidence rate is ~3-fold higher in adults older than 60y, when compared with younger subjects (Laupland et al. 2008). In addition, LDL cholesterol inhibits bacterial endotoxin (Weinstock et al. 1992), whose presence in the blood increases during aging (Ghosh et al. 2015). In support of the link between circulating cholesterol with infectious agents, in the older adults of Weverling-Rijnsburger et al. (1997), cholesterol values greater than 251 mg/dL (solid black line) were associated with significantly decreased infectious disease-related mortality, when compared with values less than 193 mg/dL:

infect mort

So if we’re better able to keep infectious agents out of our blood, that would be expected to reduce the need for elevated circulating cholesterol during aging. How can we do that?

One approach involves increased dietary fiber. Fermentation of dietary fiber by gut bacteria produces short-chain fatty acids, which improve gut barrier function (Chen et al. 2013), and decrease cholesterol synthesis (Wright et al. 1990). However, older adults do not eat high-fiber diets, as values of only ~19g/day have been reported (Lustgarten et al. 2014). In contrast, dietary fiber intakes greater than only 29g/day are associated with less infectious disease (and all-cause mortality) risk (Park et al. 2011). So definitely eating at least 29g fiber/day is important, but is that amount optimal to minimize the need for elevated cholesterol during aging?

In a 2-week study of the role of dietary fiber on circulating cholesterol, subjects that ate only 10g fiber/1000 calories did not significantly reduce their baseline total cholesterol values from ~182 mg/dL (Jenkins et al. 2001). In contrast, a dietary fiber intake of 19g/1000 calories reduced baseline total cholesterol from 185 to 150 mg/dL, and subjects that ate even more fiber than that, 55g/1000 calories reduced their total cholesterol values from ~182 to 142 mg/dL, a drop that was also significantly different compared with the 19g fiber/1000 calorie group.

Collectively, these data suggest that to maximally boost gut barrier function, thereby minimizing circulating infectious agents and the need for elevated circulating cholesterol during aging, a very-high fiber-diet may be important. Accordingly, my average daily fiber intake is ~100 g/day on a 2300 calorie diet, resulting in ~43g fiber/1000 calories. Based on this, I don’t expect for my total cholesterol values to change during aging, as my gut barrier function will be optimal, and infectious agents in my blood will be minimized.

To add some specificity to this approach, 2 additional measurements may be important: serum albumin and HDL cholesterol. In agreement with the studies of Weverling-Rijnsburger et al. and Schupf et al., in a 5-year study of 4,128 older adults (average age, ~79y), those with total cholesterol values less than 160 mg/dL had significantly higher all-cause mortality risk, compared with values greater than 240 mg/dL (Volpato et al. 2001):

low tc mortl

However, when considering subjects’ albumin and HDL cholesterol levels, the differential mortality risk was abolished. Subjects that had low total cholesterol but also high (within-range) albumin and HDL had improved survival compared to the higher cholesterol groups:

adj tc mort for alb hdl

If your total cholesterol values are less than 160 mg/dL, what serum albumin and HDL values should you shoot for? As shown below, albumin levels greater than 38 g/L and HDL values greater than 47 mg/dL were associated with maximally reduced all-cause mortality risk in subjects with total cholesterol values less than 160 mg/dL (Volpato et al. 2001):

volpato

8/15/2020: Video update!

If you’re interested, please have a look at my book!

References

Bhakdi S, Tranum-Jensen J, Utermann G, Füssle R. Binding and partial inactivation of Staphylococcus aureus alpha-toxin by human plasma low density lipoprotein. J Biol Chem. 1983 May 10;258(9):5899-904.

Chen H, Mao X, He J, Yu B, Huang Z, Yu J, Zheng P, Chen D. Dietary fibre affects intestinal mucosal barrier function and regulates intestinal bacteria in weaning piglets. Br J Nutr. 2013 Nov;110(10):1837-48.

Eaton SB, Eaton SB 3rd, Konner MJ. Paleolithic nutrition revisited: A twelve-year retrospective on its nature and implications. Eur J Clin Nutr. 1997 Apr;51(4):207-16.

Fulks M, Stout RL, Dolan VF. Association of cholesterol, LDL, HDL, cholesterol/ HDL and triglyceride with all-cause mortality in life insurance applicants. J Insur Med. 2009;41(4):244-53.

Ghosh S, Lertwattanarak R, Garduño Jde J, Galeana JJ, Li J, Zamarripa F, Lancaster JL, Mohan S, Hussey S, Musi N. Elevated muscle TLR4 expression and metabolic endotoxemia in human agingJ Gerontol A Biol Sci Med Sci. 2015 Feb;70(2):232-46.

Jenkins DJ, Kendall CW, Popovich DG, Vidgen E, Mehling CC, Vuksan V, Ransom TP, Rao AV, Rosenberg-Zand R, Tariq N, Corey P, Jones PJ, Raeini M, Story JA, Furumoto EJ, Illingworth DR, Pappu AS, Connelly PW. Effect of a very-high-fiber vegetable, fruit, and nut diet on serum lipids and colonic function. Metabolism. 2001 Apr;50(4):494-503.

Laupland KBRoss TGregson DBStaphylococcus aureus bloodstream infections: risk factors, outcomes, and the influence of methicillin resistance in Calgary, Canada, 2000-2006. J Infect Dis. 2008 Aug 1;198(3):336-43.

Lustgarten MS, Price LL, Chalé A, Fielding RA. Metabolites related to gut bacterial metabolism, peroxisome proliferator-activated receptor-alpha activation, and insulin sensitivity are associated with physical function in functionally-limited older adults. Aging Cell. 2014 Oct;13(5):918-25.

Mansoor N, Vinknes KJ, Veierød MB, Retterstøl K. Effects of low-carbohydrate diets v. low-fat diets on body weight and cardiovascular risk factors: a meta-analysis of randomised controlled trials. Br J Nutr. 2016 Feb;115(3):466-79.

Park Y, Subar AF, Hollenbeck A, Schatzkin A. Dietary fiber intake and mortality in the NIH-AARP diet and health study. Arch Intern Med. 2011 Jun 27;171(12):1061-8.

Schmutz EA, Zimmermann MB, Rohrmann S. The inverse association between serum 25-hydroxyvitamin D and mortality may be modified by vitamin A status and use of vitamin A supplements. Eur J Nutr. 2016 Feb;55(1):393-402.

Schupf N, Costa R, Luchsinger J, Tang MX, Lee JH, Mayeux R. Relationship Between Plasma Lipids and All-Cause Mortality in Nondemented Elderly. J Am Geriatr Soc. 2005 Feb;53(2):219-26.

Targonski PV, Jacobson RM, Poland GA. Immunosenescence: role and measurement in influenza vaccine response among the elderly. Vaccine. 2007 Apr 20;25(16):3066-9.

Vasto S, Scapagnini G, Rizzo C, Monastero R, Marchese A, Caruso C. Mediterranean diet and longevity in Sicily: survey in a Sicani Mountains population. Rejuvenation Res. 2012 Apr;15(2):184-8.

Volpato S, Leveille SG, Corti MC, Harris TB, Guralnik JM. The value of serum albumin and high-density lipoprotein cholesterol in defining mortality risk in older persons with low serum cholesterolJ Am Geriatr Soc. 2001 Sep;49(9):1142-7.

Weinstock C, Ullrich H, Hohe R, Berg A, Baumstark MW, Frey I, Northoff H, Flegel WA. Low density lipoproteins inhibit endotoxin activation of monocytes. Arterioscler Thromb. 1992 Mar;12(3):341-7.

Weverling-Rijnsburger AW, Blauw GJ, Lagaay AM, Knook DL, Meinders AE, Westendorp RG. Total cholesterol and risk of mortality in the oldest old. Lancet. 1997 Oct 18;350(9085):1119-23.

Wright RS, Anderson JW, Bridges SR. Propionate inhibits hepatocyte lipid synthesis. Proc Soc Exp Biol Med. 1990 Oct;195(1):26-9.

Blood Test Analysis: 100 – 111y (Centenarians, Semi- and Super-Centenarians)

In order to slow aging, it’s important to know how circulating biomarkers change during aging, and how these biomarkers are associated with risk of death for all causes. In this video, I discuss blood test data for the oldest old, including centenarians (100 – 104y), semi-centenarians (105 – 109y), and super-centenarians (110y+).

 

Eat more green leafy vegetables, reduce mortality risk?

Vitamin K is found in 2 predominant forms, Vitamin K1 (phylloquinone), found almost exclusively in green leafy vegetables, and Vitamin K2 (Menaquinone), found in fermented foods, organ meats, meat, butter and eggs. In the data below (Juanola-Falgarona et al. 2014), we see that Vitamin K1 (phylloquinone) is negatively associated with death from all causes:

all cause mortl phylo

Death from all causes was assessed based on the average value for four groups of Vitamin K1 intake: 171 ug/day = blue line, 276 ug/day =red line, 349 ug/day = green line and 626 ug/day = the yellow line. In the data above, Vitamin K1 values less than 349 ug/day are about the same in terms of all-cause mortality risk. However, those who ate 626 ug/day of Vitamin K1 had about half of the mortality risk compared to the lower K1 intake groups! Interestingly, the RDA for Vitamin K, at 90 ug/day seems to be outdated, based on the data above. Also, Vitamin K2 was not associated with all-cause mortality risk, as shown below:

k2 all cause

Based on the K1 mortality data, 626 ug/day seems like a good goal. However, osteocalcin is a Vitamin K-dependent protein that has been shown to be maximally active in the presence of 1000 ug of Vitamin K1 (Binkley et al. 2002)! Osteocalcin is involved in pathways that decline with aging: insulin secretion and β-cell proliferation in the pancreas, energy expenditure by muscle, insulin sensitivity in adipose tissue, muscle and liver, and increased testosterone production (Karsenty and Ferron 2012). Therefore, getting 1000 ug+ per day of Vitamin K1 may optimize all of these functions and, decrease mortality risk!

What’s the take home from these data? Eat more leafy greens! How much is needed to get 1000 ug  per day? Shown below is a short list of foods rich in Vitamin K and the serving size needed to reach 1000 ug. Approximately 4 ounces of cooked kale or 7 oz. of raw spinach will suffice, and at a low calorie yield. Other foods, like broccoli, brussel sprouts or romaine lettuce would need to be consumed in far greater amounts to reach 1000 ug.

k osteo

What’s my daily K1 intake? Shown below is my 7-day average (7/16/2015 – 7/22/2015) for K intake, derived almost exclusively from plant sources. 1379 ug/day puts me well above the 626 ug/day that was associated with reduced mortality risk, and above the 1000 ug/day needed for maximal osteocalcin activation.

my k intake

Here’s this post in video form!

If you’re interested, please have a look at my book!
https://www.amazon.com/dp/B01G48A88A?ref_=k4w_oembed_omIChDjq2EkggX&tag=kpembed-20&linkCode=kpd

References:

Binkley NC, Krueger DC, Kawahara TN, Engelke JA, Chappell RJ, Suttie JW. A high phylloquinone intake is required to achieve maximal osteocalcin gamma-carboxylation. Am J Clin Nutr. 2002 Nov;76(5):1055-60.

Juanola-Falgarona M, Salas-Salvadó J, Martínez-González MÁ, Corella D, Ostrich R, Ros E, Fitó M, Arós F, Gómez-Gracia E, Fiol M, Lapetra J, Basora J, Lamuela-Raventós RM, Serra-Majem L, Pintó X, Muñoz MÁ, Ruiz-Gutiérrez V, Fernández-Ballart J, Bulló M. Dietary intake of vitamin K is inversely associated with mortality risk. J Nutr. 2014 May;144(5):743-50.

Karsenty G, Ferron M. The contribution of bone to whole-organism physiologyNature. 2012 Jan 18;481(7381):314-20.

Optimizing Biological Age With Aging.ai: Blood Urea Nitrogen

Blood urea nitrogen (BUN) is one of the 19 variables found on the biological age calculator, aging.ai. It measures the amount of nitrogen, as contained in urea (i.e., blood urea nitrogen, BUN) in your blood. The reference range for BUN is 5 – 20 mg/dL, but within that range, what’s optimal?

First, BUN increases during aging, from 11 – 13 mg/dL in 20 yr olds to 20 – 22 mg/dL in 90 yr olds (Wang et al. 2017):

Screen Shot 2019-11-21 at 5.55.45 AM

The importance of the age-related increase in BUN is illustrated by the finding that risk of death for all causes increases above 15 mg/dL:

BUN

Also note that maximally decreased risk for all cause mortality was associated with BUN values between 5 – 15 mg/dL. In addition, even though a BUN value = 20 mg/dL is technically within the reference range, risk of death for all causes would be 50% higher when compared with someone that had BUN levels between 5 – 15 mg/dL. Collectively, based on the aging and all-cause mortality data, I’d argue that 5 – 13 mg/dL may be the optimal range for BUN.

Assuming normal kidney function (see https://michaellustgarten.wordpress.com/2019/11/18/optimizing-biologic-age-creatinine/), if your BUN is higher than 15 mg/dL, can it be reduced? Note that urea production is almost perfectly correlated (r = 0.98) with dietary protein intake (Young et al. 2000):
urea nitrog

In other words, the main source of dietary nitrogen is protein, so if you eat a lot of protein, you’ll make a lot of urea. Circulating levels of urea can be easily calculated by measuring BUN, via: Urea [mg/dL]= BUN [mg/dL] * 2.14). Therefore, measuring BUN can then be used to determine if your protein intake is too high or too low.

What’s my BUN? As shown below, I’ve measured BUN 22 times since 2015. In line with the Young et al. (2000) data that showed an almost perfectly linear correlation between dietary nitrogen intake with urea production, similarly, as my dietary protein intake has increased, so have my BUN levels. The correlation between my dietary protein intake with BUN is strong (= 0.76, R^2 = 0.575, p-value = 4.3E-05):

upd bun

Note that my BUN is (purposefully) below 15 mg/dL, the upper limit for reduced all-cause mortality risk in Solinger and Rothman (2013), and within the 11 – 13 mg/dL range reported for the 20 yr olds of Wang et al. (2017).

For more recent tracked data, see the video! 

References

Solinger AB, Rothman SI. Risks of mortality associated with common laboratory tests: a novel, simple and meaningful way to set decision limits from data available in the Electronic Medical Record. Clin Chem Lab Med. 2013 Sep;51(9):1803-13.

Wang Z, Li L, Glicksberg BS, Israel A, Dudley JT, Ma’ayan A. Predicting age by mining electronic medical records with deep learning characterizes differences between chronological and physiological ageJ Biomed Inform. 2017 Dec;76:59-68. doi: 10.1016/j.jbi.2017.11.003.

Young VR, El-Khoury AE, Raguso CA, Forslund AH, Hambraeus L. Rates of urea production and hydrolysis and leucine oxidation change linearly over widely varying protein intakes in healthy adults. J Nutr. 2000 Apr;130(4):761-6.

If you’re interested, please have a look at my book!

Vitamin C: Dietary Intake And Plasma Values, What’s Optimal For Health?

How much Vitamin C (ascorbic acid) is optimal for health? To answer this question, I’ll examine the association between circulating levels of Vitamin C with all-cause mortality risk. Then, which dietary Vitamin C intake corresponds to optimal plasma levels? Let’s have a look!

A variety of studies have investigated associations between plasma (or serum) Vitamin C with all-cause mortality risk:

  • In a 4-year study of 1,115 older adults (average age ~79y), plasma vitamin C values greater than 66 uM (micromolar) were associated with significantly decreased all-cause mortality risk, when compared with values less than 17 uM (Fletcher et al. 2003).
  • In a 12-year study of 725 older adults (average age, 73y), plasma vitamin C values greater than 52 uM were associated with significantly reduced all-cause mortality risk (Sahyoun et al. 1996). Interestingly, the most reduced mortality risk was found in those with plasma Vitamin C values greater than 89 uM, a value that can only be attained with dietary Vitamin C intakes greater than 1000 mg/day (more on this below!).
  • In a 16-year study of 8,453 middle-aged adults (average age ~49y), serum Vitamin C values greater than 45 uM were associated with significantly reduced all-cause mortality risk, when compared with values less than 17 uM (Simon et al. 2001).
  • In a 13-year study of 948 older adults (average age, 67y), serum Vitamin C values greater than 55 uM were associated with significantly reduced all-cause mortality risk, when compared with values less than 13.5 uM (Wang et al. 2018).
  • In a 13-year study of 1,054 older adults (average age ~76y), elevated plasma levels of Vitamin C (risk ratios were reported without the actual Vitamin C concentration) were associated with significantly decreased all-cause mortality risk (Bates et al. 2011).
  • In a 4-year study of 19,496 older adults (average age ~59y), plasma Vitamin C values greater than 48 uM in men and 59 uM in women (both in quintile 3, shown below) were associated with significantly reduced all-cause mortality risk (Khaw et al. 2001). The most reduced all-cause mortality risk included average Vitamin C values of 73 uM for men and 85 uM for women (shown below in quintile 5), values which require greater than 500 mg of dietary Vitamin C/day (more on this also below!).

C risk

Studies that show weaker or no association between the plasma Vitamin C concentration with all-cause mortality risk include Loria et al. (2000) and Jia et al. (2007). In Loria et al. (2000), 9,450 middle aged adults (~48y) were followed for 12-16 years. Men in the highest Vitamin C quartile (> 74 uM) had significantly reduced all-cause mortality risk, when compared with men in the low plasma Vitamin C group (< 28 uM). Although a similar association was identified for women, significance was lost after multivariable adjustment. In Jia et al. (2007), although plasma Vitamin C values less than 61 uM were associated with increased all-cause mortality risk in older adults (median age, ~80y) that were studied for ~7.5 years, these data were not statistically significant (p-value = 0.18). However, the study sample size (398 subjects) may have been too small to detect significant effects.

Collectively these studies show that low circulating levels of Vitamin C may be related to an increased mortality risk, whereas plasma values greater than ~50 uM are consistently associated with reduced all-cause mortality risk. How much dietary vitamin C is required to attain 50 uM+?

As shown below, the RDA for dietary Vitamin C is 90 mg for males and 75 mg for females older than 19 years (Institute of Medicine 2000).

C RDA

If you consume the RDA for Vitamin C, what plasma Vitamin C concentration will that yield? Shown below is how the plasma Vitamin C concentration varies according to ingested dose (Levine et al. 1996). Consuming the RDA value for Vitamin C yields a plasma Vitamin C value of 20-30 uM. From the studies listed above, that would put you in the increased all-cause mortality risk group! How much dietary Vitamin C would be needed to achieve plasma values greater than 50 uM? From the plot, we see that a dietary Vitamin C intake at double the RDA would be necessary. Furthermore, because 2 studies have reported decreased all-cause mortality risk at plasma Vitamin C values greater than 66 uM, dietary intakes intake between 500-1000+ mg/day may be necessary:

C dose

Which foods are  Vitamin C-rich? As shown below, sweet peppers (yellow, red, and green) are the All-Stars for Vitamin C content per 100 calories:

C foods

What’s my average daily Vitamin C intake? Shown below is my average daily Vitamin C intake, 971 mg/day (red line) over the past 400+ days:

C.png

Note that I don’t supplement with Vitamin C, and that amount is completely from food. Also, I generally split my Vitamin C intake throughout the day, with about 2/3 in the morning and the remaining at night, to try to keep my circulating Vitamin C levels relatively saturated at > 70 uM. I haven’t measured my circulating C levels (yet), but that’s on the to do list!

With the goal of optimizing plasma levels of Vitamin C, it is also important to monitor dietary sodium intake. Intestinal absorption of Vitamin C requires dietary sodium (Friedman and Zeidel 1999). As shown below, 1 ascorbate ion (asc-) is absorbed from the intestinal lumen into intestinal epithelial cells in the presence of 2 sodium (Na+) ions. Vitamin C can then diffuse into the blood as Asc- or as dehydroascorbate (DHA):

na asc transport

Accordingly, based on my average dietary Vitamin C intake of 971 mg/day, to maximize absorption, a corresponding dietary sodium intake of 1940 mg would also be necessary.

These data are now in video format!

 

References

Bates CJ, Hamer M, Mishra GD. Redox-modulatory vitamins and minerals that prospectively predict mortality in older British people:the National Diet and Nutrition Survey of people aged 65 years and overBr J Nutr. 2011 Jan;105(1):123-32.

Fletcher AE, Breeze E, Shetty PS. Antioxidant vitamins and mortality in older persons: findings from the nutrition add-on study to the Medical Research Council Trial of Assessment and Management of Older People in the Community. Am J Clin Nutr. 2003 Nov;78(5):999-1010.

Friedman PA, Zeidel ML. Victory at C. Nat Med. 1999 Jun;5(6):620-1.

Institute of Medicine. Food and Nutrition Board. Dietary Reference Intakes for Vitamin C, Vitamin E, Selenium, and Carotenoids. Washington, DC: National Academy Press, 2000.

Jia X, Aucott LS, McNeill G. Nutritional status and subsequent all-cause mortality in men and women aged 75 years or over living in the community. Br J Nutr. 2007 Sep;98(3):593-9.

Khaw KT, Bingham S, Welch A, Luben R, Wareham N, Oakes S, Day N. Relation between plasma ascorbic acid and mortality in men and women in EPIC-Norfolk prospective study: a prospective population study. European Prospective Investigation into Cancer and Nutrition. Lancet. 2001 Mar 3;357(9257):657-63.

Levine M, Conry-Cantilena C, Wang Y, Welch RW, Washko PW, Dhariwal KR, Park JB, Lazarev A, Graumlich JF, King J, Cantilena LR. Vitamin C pharmacokinetics in healthy volunteersevidence for a recommended dietary allowance. Proc Natl Acad Sci U S A. 1996 Apr 16;93(8):3704-9.

Loria CM, Klag MJ, Caulfield LE, Whelton PK. Vitamin C status and mortality in US adults. Am J Clin Nutr. 2000 Jul;72(1):139-45.

Sahyoun NR, Jacques PF, Russell RM. Carotenoids, vitamins C and E, and mortality in an elderly population. Am J Epidemiol. 1996 Sep 1;144(5):501-11.

Simon JA, Hudes ES, Tice JA. Relation of serum ascorbic acid to mortality among US adults. J Am Coll Nutr. 2001 Jun;20(3):255-63.

Wang SM, Fan JH, Taylor PR, Lam TK, Dawsey SM, Qiao YL, Abnet CC. Association of plasma vitamin C concentration to total and cause-specific mortality: a 16-year prospective study in ChinaJ Epidemiol Community Health. 2018 Dec;72(12):1076-1082.

Blood Testing: What’s Optimal For Triglycerides?

In terms of all-cause mortality risk, is the reference range for circulating triglycerides (TG, <150 mg/dL) optimal?

A meta-analysis of 38 studies in 360,556 subjects with a median age of 48y and a 12-year follow-up reported lowest all-cause mortality risk for subjects with TG values less than 90 mg/dL (equivalent to ~1 mmol; Liu et al. 2013). As shown below, each successive 90 mg/dL increase was associated with a 12% higher all-cause mortality risk. A person with a value closer to the high end of the reference range, ~150 would have a ~7% increased mortality risk compared someone with a value ~90. In other words, there would be 7 more deaths per 100 total people at a TG value of 150, compared with the death rate for people with values less than 90.

tg mortal

Added importance for the association between TG values less than 90 with all-cause mortality risk come from studies of people who have lived longer than 100 years, centenarians. As shown below, triglyceride values less than 101 mg/dL have been reported in 9 of 11 centenarian studies:

tg mort

What’s my TG value? As shown below, I’ve measured triglycerides 23 times since 2015, with an average value of 52 mg/dL:tg 2020

With the goal of keeping triglyceride levels low, are there dietary factors that influence it? When compared with my dietary data, the strongest correlation (r = 0.73, R2=0.5339) is present for triglycerides with my calorie intake. In other words, a higher daily calorie intake is associated with higher levels of triglycerides:

tg vs cals 2020

Based on this correlation, should my triglycerides start to rise in the future, a first step would be reducing my average daily calorie intake, which since October 2019 has been ~2550 calories/day.

 

If you’re interested, please have a look at my book!

References

Liu J, Zeng FF, Liu ZM, Zhang CX, Ling WH, Chen YM. Effects of blood triglycerides on cardiovascular and all-cause mortality: a systematic review and meta-analysis of 61 prospective studies. Lipids Health Dis. 2013 Oct 29;12:159.

Resting Heart Rate, Heart Rate Variability: January 2020 Update

How’s my progress on the road to achieving a resting heart rate (RHR) as close to 40 beats per minute (bpm) as possible? Shown below is my RHR data for August 2018-Jan 2019, which corresponds to the 6-month period after I started tracking RHR. When compared with that period, am I still making year-over-year progress?

jan hr

First, note that my Jan 2019 RHR value of 47.4 bpm seems dramatically reduced when compared with Aug-Dec 2018. My computer crashed in Jan 2019, and I lost 4 days of January 2019 RHR data, with remaining data for 27 days. Accordingly, I didn’t expect to be better than that, year-over-year. Nonetheless,  my average RHR for Jan 2020 is 46.9 bpm, which is superficially better, but it isn’t statistically different from Jan 2019 (p = 0.13). However, my RHR is still going in the right direction!

What about my heart rate variability (HRV)? Relative to Jan 2019 (56.6), my HRV in Jan 2020 was significantly higher (76; p=0.003), but note that I didn’t additionally improve my HRV relative to December 2019 (86.3).

hrvjan2

I’ve been consistent with my exercise program, including weekly workouts (3-4x, ~1 hr each session) and walking (15-20 miles), so are there other variables that may explain the sudden increase in HRV from Nov 2019-Jan 2020? During that time, I’ve been cutting my calorie intake by a small amount (~100-200 cals/day) below my body weight maintenance intake, with the goal of getting leaner. As a result, I’ve slowly decreased my body weight from 157 to 154 during that time. Although there is a weak negative correlation between my body weight with HRV (R2=0.0553), this association is statistically significant (p=0.024). So reducing body weight may have played a role in the sudden HRV increase:

hrv bw

For those who may have missed my other post updates for RHR and/or HRV:
Dec 2019 update: https://michaellustgarten.wordpress.com/2020/01/01/resting-heart-rate-heart-rate-variability-december-2019-update/

Oct, Nov 2019 update: https://michaellustgarten.wordpress.com/2019/12/05/resting-heart-rate-heart-rate-variability-still-making-progress/

Sept 2019 update: https://michaellustgarten.wordpress.com/2019/10/08/resting-heart-rate-year-over-year-update/

Also, why a RHR as close to 40 bpm may be optimal: https://michaellustgarten.wordpress.com/2019/02/02/resting-heart-rate-whats-optimal/

 

If you’re interested, please have a look at my book!