Hyperhomocysteinemia and risk of incident cognitive outcomes: An updated dose-response meta-analysis of prospective cohort studies: https://pubmed.ncbi.nlm.nih.gov/30826…
Association between Homocysteine Levels and All-cause Mortality: A Dose-Response Meta-Analysis of Prospective Studies: https://www.nature.com/articles/s4159…
In November 2020, I made a HDL video based on a meta-analysis in ~3.4 million subjects that was published in July 2020. In Dec 2020, a larger study (n=15.8 million subjects) was published-those data are presented in the video, and compared against the meta-analysis.
In addition, I’ve tested my HDL 2 more times since November 2020, so how’s my progress for getting it into the optimal range? Also, I attempt to derive clinical significance by identifying correlations for higher HDL with lower Lp(a) and hs-CRP.
LDL is arguably the most debated biomarker in terms of what’s optimal for health. In the video, I present data showing that 100 – 140, not 50 – 70 mg/dL may be optimal in terms of minimizing disease risk and maximizing longevity.
After going on Joe Rogan’s podcast, Paul Saladino, MD, posted his show notes, which included his blood test results. Based on that data, is his biological age optimal while on a carnivore diet?
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+).
My latest blood test results are in-how’s my biological age? In the video I discuss my dietary approach prior to my latest blood test, the blood test results, and my plan to improve them going forward.
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):
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:
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.
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 (r = 0.76, R^2 = 0.575, p-value = 4.3E-05):
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. Predictingage by miningelectronicmedicalrecords with deeplearningcharacterizesdifferences between chronological and physiologicalage. J 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!
Michael Lustgarten 