High or low HDL and LDL in athletes

Abnormalities in the lipidogram in people who exercise occur more often than is commonly thought. Low "good" cholesterol, high "bad" and sometimes unexpectedly high HDL - each of these situations has its own reasons. The editors analysed what can be behind the changes in HDL and LDL in athletes and how to act to return the indicators to a safe range.

Briefly about norms and goals

For lipids, the concept of "normal" differs from most other analyses. The reference interval in the laboratory form often reflects not optimal, but typical values ​​for the population. However, in today's society, the "typical" level of LDL is already elevated compared to what is considered safe.

Therefore, for LDL-C, the 2019 international ESC/EAS guidelines do not use a “norm” but target values ​​that depend on overall cardiovascular risk. For people at low risk, the guideline is less than 3.0 mmol/L, for moderate - less than 2.6, for high and very high - even lower.

For HDL-C, a value below approximately 1.0 mmol/L in men and 1.2 mmol/L in women is considered a marker of increased risk. The guidelines do not set target values ​​for HDL, because its artificial increase has not proven beneficial.

Interpretation always takes into account the complete picture: triglycerides, non-HDL cholesterol, blood pressure, smoking, glucose, family history. The same level of LDL may be acceptable for one person and require treatment for another.

Low HDL: the main causes

In the sports environment, the most obvious cause of a sharp decrease in HDL is anabolic androgenic steroids. Hartgens et al. (2004) observed significant reductions in HDL and apolipoprotein A-I in bodybuilders who self-administered steroids. The mechanism is associated with the activation of liver lipase, which accelerates the destruction of HDL particles. Oral 17-alpha-alkylated drugs have a particularly pronounced effect.

After discontinuing the use, the lipid profile gradually recovers, but not immediately - it usually takes weeks or months. However, repeated cycles represent a multi-year stay with an adverse profile, which, according to the Endocrine Society scientific statement (Pope et al., 2014), is one of the mechanisms of increased cardiovascular risk in this population.

Other causes of low HDL: smoking, being overweight, insulin resistance and high triglycerides, a very low-fat diet high in refined carbohydrates, and a sedentary lifestyle. There are also genetic forms, when low HDL is transmitted in the family.

Certain medications also lower HDL, including certain beta-blockers and progestins with androgenic activity. The doctor takes them into account when evaluating the analysis.

High HDL: Is it always a good thing?

High HDL in endurance athletes is common. Regular aerobic exercise moderately increases this indicator, which was confirmed by the meta-analysis of Kodama et al. (2007). In this context, values ​​of 1.6–2.0 mmol/L usually reflect a favourable metabolic profile.

At the same time, the concept of "the higher the better" does not work. A large Danish cohort study by Madsen et al (2017) found that extremely high HDL was associated with higher mortality compared with moderate values. The reasons for this are still being studied; genetic variants that alter particle function and alcohol exposure are among the possible ones.

Excessive alcohol consumption is one of the common causes of high HDL, which also damages the liver, heart, and blood pressure. Therefore, elevated HDL in combination with elevated GGT or ALT is a reason to review habits.

It is also important to remember that high HDL does not neutralize high LDL. If LDL is elevated, the atherogenic burden remains, even when the "good" cholesterol is affected.

High and low LDL: causes

The most significant dietary factor in increasing LDL is saturated fatty acids. A systematic review prepared for WHO (Mensink, 2016) found that replacing saturated fat with polyunsaturated fat lowers LDL. During the period of gaining weight, the diet of athletes often contains a lot of fatty meat, butter and cheese, which can raise the indicator.

Very low-carbohydrate, high-fat diets markedly increase LDL in some people. This reaction is individual and not manifested in everyone, so people on a keto diet should monitor their lipid profile.

Medical causes include familial hypercholesterolaemia, hypothyroidism, cholestatic liver disease, nephrotic syndrome, and some medications. A familial form should be suspected when LDL is higher than about 4.9 mmol/L in an adult, especially if there is a family history of early heart attacks. This level, according to the ESC/EAS guidelines, in itself puts a person in a high-risk group.

Anabolic steroids often increase LDL, although the effect varies by substance. Together with a decrease in HDL, this creates a particularly unfavourable relationship.

Low LDL is usually not a problem and is a target of therapy in people taking statins. But unexpectedly low values ​​without treatment may indicate hyperthyroidism, including that caused by taking thyroid hormones, severe energy deficiency, or liver disease.

What to do in case of deviations

The first step is always to re-analyze under standard conditions to eliminate random fluctuations. Next is the search for the cause and correction of the lifestyle. Medical treatment is prescribed only by a doctor.

1. Repeat the analysis after 2-4 weeks in the same laboratory, without acute diseases and unusual loads.
2. Rule out secondary causes: thyroid function (TSH), liver tests, glucose, urinalysis for protein, drug list.
3. Adjust your diet: less saturated fat, more unsaturated (olive oil, nuts, fish), more dietary fibre from vegetables, legumes and whole grains.
4. Maintain aerobic activity and normal body weight; give up smoking.
5. Avoid hormonal drugs without medical indications - this is the most effective way to restore HDL, if the cause lies in them.

If LDL remains above target after lifestyle changes, or there are signs of hereditary hypercholesterolaemia, a doctor may prescribe lipid-lowering therapy. He may add tests for apolipoprotein B and lipoprotein(a) to clarify the risk.

Supplements such as plant sterols or psyllium may modestly lower LDL as an adjunct to diet, but are not a substitute for treatment at high risk.

Editorial conclusions

Low HDL in an athlete is most often associated with anabolic steroids, smoking or metabolic disorders, and high - with aerobic training, genetics or alcohol. High LDL is saturated fat, heredity, hypothyroidism, or hormonal drugs.

Main target is LDL and total atherogenic burden, not HDL “fit”. Lifestyle gives a tangible effect, but in case of high risk, the decision about medication is made by the doctor.

The editors also recommend reading "HDL and LDL: what the analysis shows and why it is important for an athlete", "Apolipoprotein B above or below the norm: causes in athletes and what to do" and "Triglycerides above or below the norm: causes in athletes and what to do".

List of used literature

1. Mach F, Baigent C, Catapano AL, et al. 2019 ESC/EAS Guidelines for the management of dyslipidaemias: lipid modification to reduce cardiovascular risk. Eur Heart J. 2020;41(1):111–188.
2. Hartgens F, Rietjens G, Keizer HA, et al. Effects of androgenic-anabolic steroids on apolipoproteins and lipoprotein (a). Br J Sports Med. 2004;38(3):253–259.
3. Pope HG Jr, Wood RI, Rogol A, et al. Adverse health consequences of performance-enhancing drugs: an Endocrine Society scientific statement. Endocr Rev. 2014;35(3):341–375.
4. Kodama S, Tanaka S, Saito K, et al. Effect of aerobic exercise training on serum levels of high-density lipoprotein cholesterol: a meta-analysis. Arch Intern Med. 2007;167(10):999–1008.
5. Madsen CM, Varbo A, Nordestgaard BG. Extreme high high-density lipoprotein cholesterol is paradoxically associated with high mortality in men and women. Eur Heart J. 2017;38(32):2478–2486.
6. Mensink RP. Effects of saturated fatty acids on serum lipids and lipoproteins: a systematic review and regression analysis. Geneva: World Health Organization; 2016.
7. Grundy SM, Stone NJ, Bailey AL, et al. 2018 AHA/ACC/AACVPR/AAPA/ABC/ACPM/ADA/AGS/APhA/ASPC/NLA/PCNA Guideline on the Management of Blood Cholesterol. Circulation. 2019;139(25):e1082–e1143.