How Nutritionists Can Help Clients Read Key Blood Tests

Highlights:

• Understanding the implications of a lipid panel, blood glucose measurements, and inflammation markers can help your client see their health and longevity progress
• Routine annual blood tests can help you and your clients decide which lifestyle interventions to prioritize

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Introduction

Every annual checkup at a general practitioner typically includes a blood test to reveal early signs of non-communicable diseases. For you as a nutritionist or health coach, this is a great opportunity to help your client interpret the results and explain how each affects health and longevity. In this article, we will focus on those that can be modulated by diet and lifestyle interventions, such as lipids, blood glucose, and inflammation markers.

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Lipid panel

The lipid panel is commonly included in routine annual blood tests because it can say a lot about the health status of the cardiovascular system. It is made up of different types of cholesterol and triglycerides, each of which has a different impact on disease risk.

Elevated low-density lipoprotein cholesterol (LDL-C) is well-established as one of the main risk factors for heart disease. What is not as widely discussed is that even slight elevations of LDL cholesterol can increase the risk if they last for a long time. For example, studies show that 16 years of exposure to moderate LDL levels produce a similar coronary heart disease risk as 8 years of high LDL or 4 years of very high LDL (1). This is a solid reason to keep LDL-C levels under 130 mg/dL, which is the border between normal and moderate. For people with a family history of cardiovascular disease, the target would be even lower than that. High LDL cholesterol level is defined as anything above 160 mg/dL and very high above 190 mg/dL.

On the other hand, high-density lipoprotein cholesterol (HDL-C) appears to be protective. Studies show that increased levels of HDL-C are associated with a lower risk of cardiovascular disease (CVD) and a longer lifespan. Each additional 16 mg/dL of HDL-C was associated with an 8% decreased risk of CVD (2). Overall, men would be at risk with HDL-C levels below 40 mg/dL and women below 50 mg/dL. Ideally, both men and women should aim for 60 mg/dL or above.

High levels of triglycerides (TG) are also considered a risk factor. Levels below 150 mg/dL would be in the norm, 150 to 199 mg/dL borderline high, 200 to 499 mg/dL high, and above 500 mg/dL very high. Triglycerides are most useful when observed in relation to HDL-C. This relationship is most commonly expressed as the atherogenic index of plasma (AIP), which is calculated as a logarithm of TG divided by HDL-C. A low risk of cardiovascular disease is associated with AIP values between −0.3 to 0.1, a medium risk with 0.1 to 0.24, and high risk with an index above 0.24 (3).

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Blood glucose

Monitoring blood glucose is an effective way to detect early signs of type 2 diabetes and even reveal cardiovascular disease risks. This is why fasting blood glucose (FBG) is also commonly included in your client’s annual blood tests. Normal FBG level falls between 70 – 99 mg/dL, elevated is 100 – 125 mg/dL, and if two separate tests show 126 mg/dL or higher, type 2 diabetes is diagnosed.

For clients interested in longevity, studies suggest that FBG can be further optimized. Research shows that people with FBG in the high normal range of 95 – 99 mg/dl have significantly higher cardiovascular disease risk than people who remain below 80 mg/dl (4). Research also highlights that people with FBG between 91 and 99 mg/dl have a 3-fold increase in type 2 diabetes risk compared to those with levels less than 83 mg/dl (5). Continuous glucose monitoring (CGM) is becoming available even for healthy populations, and it can be a powerful tool for prevention. CGM sensors are installed under the skin to monitor glucose levels 24 hours a day. It offers detailed information about FBG as well as blood sugar after meals. Research on CGM reveals that fasting glucose in healthy people ranges from 80 to 86 mg/dl (6). The evidence suggests that FBG should be close to 80 mg/dL.

Another commonly used blood sugar marker is hemoglobin A1C (HbA1C). It measures the percentage of red blood cells saturated with glucose. Red blood cells live approximately 110 – 120 days which means HbA1C reveals average blood sugar levels over the past 2 – 3 months. This makes it a useful marker that is not affected by short-term hormonal surges, stress, physical activity, or fasted state prior to testing (7). Healthy HbA1C ranges between 4 – 5.6 %, above 5.7 % is considered prediabetic, and above 6.5 % diabetic results (8).

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Inflammation

Blood tests commonly include C-reactive protein (CRP), a nonspecific marker of inflammation. Chronically elevated CRP concentrations are associated with an increased risk of cardiovascular disease, type 2 diabetes, Alzheimer’s disease, hemorrhagic stroke, Parkinson’s disease, and age-related macular degeneration (9). A study on the oldest-old, which included 2206 participants with a median age of 93, found that elevated high sensitivity CRP (hsCRP) concentrations were associated with a higher risk of all-cause mortality. Measures of less than 1 mg/L are considered low risk, 1 – 3 mg/L pose moderate risk, and anything above 3 mg/L is high risk (10).

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Conclusions

Many primary blood test markers such as LDL cholesterol, atherogenic index of plasma, fasting blood glucose, and C-reactive protein can offer a great window into your client’s health and longevity journey. Helping them interpret their results and translate improvements into years gained can be a powerful motivation. Explaining optimal values within normal ranges of these markers can be an added benefit and something to guide which lifestyle interventions should take priority.

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References

1. Ueda P, Gulayin P, Danaei G. Long-term moderately elevated LDL-cholesterol and blood pressure and risk of coronary heart disease. PloS one 2018;13(7):e0200017. 10.1371/journal.pone.0200017
2. Li X, Ploner A, Wang Y, Zhan Y, Pedersen NL, Magnusson PK, Jylhävä J, Hägg S. Clinical biomarkers and associations with healthspan and lifespan: Evidence from observational and genetic data. EBioMedicine 2021;66:103318. 10.1016/j.ebiom.2021.103318
3. Dobiásová M. [AIP--atherogenic index of plasma as a significant predictor of cardiovascular risk: from research to practice]. Vnitrni lekarstvi 2006;52(1):64-71. PMID: 16526201
4. Park C, Guallar E, Linton JA, Lee DC, Jang Y, Son DK, Han EJ, Baek SJ, Yun YD, Jee SH, Samet JM. Fasting glucose level and the risk of incident atherosclerotic cardiovascular diseases. Diabetes care 2013;36(7):1988-93. 10.2337/dc12-1577
5. Brambilla P, La Valle E, Falbo R, Limonta G, Signorini S, Cappellini F, Mocarelli P. Normal fasting plasma glucose and risk of type 2 diabetes. Diabetes care 2011;34(6):1372-4. 10.2337/dc10-2263
6. Rodriguez-Segade S, Rodriguez J, Camiña F, Fernández-Arean M, García-Ciudad V, Pazos-Couselo M, García-López JM, Alonso-Sampedro M, González-Quintela A, Gude F. Continuous glucose monitoring is more sensitive than HbA1c and fasting glucose in detecting dysglycaemia in a Spanish population without diabetes. Diabetes research and clinical practice 2018;142:100-9. 10.1016/j.diabres.2018.05.026
7. Hanna FW, Wilkie V, Issa BG, Fryer AA. Revisiting screening for type 2 diabetes mellitus: the case for and against using HbA1c. The British journal of general practice : the journal of the Royal College of General Practitioners 2015;65(633):e278-80. 10.3399/bjgp15X684637
8. Sherwani SI, Khan HA, Ekhzaimy A, Masood A, Sakharkar MK. Significance of HbA1c Test in Diagnosis and Prognosis of Diabetic Patients. Biomarker insights 2016;11:95-104. 10.4137/BMI.S38440
9. Luan YY, Yao YM. The Clinical Significance and Potential Role of C-Reactive Protein in Chronic Inflammatory and Neurodegenerative Diseases. Frontiers in immunology 2018;9:1302. 10.3389/fimmu.2018.01302
10. Wassel CL, Barrett-Connor E, Laughlin GA. Association of circulating C-reactive protein and interleukin-6 with longevity into the 80s and 90s: The Rancho Bernardo Study. The Journal of clinical endocrinology and metabolism 2010;95(10):4748-55. 10.1210/jc.2010-0473

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