HSA | FSA CARDS ARE NOW ACCEPTED

How NR1H2 (LXRβ) Affects Thyroid Function, Metabolism, and Men's Fertility Health

The thyroid gland produces hormones that regulate metabolism, energy use, and overall hormonal balance. These functions are important for men's hormone balance and fertility. The NR1H2 gene encodes Liver X receptor beta, often called LXRβ. LXRβ helps support activation of the thyroid hormone T3 in the liver and plays a role in fat regulation, cholesterol management, and glucose handling. Variations in NR1H2 can change LXRβ activity and may influence metabolic rate, body weight management, blood lipids, and insulin sensitivity.

Why this matters to you

  • Thyroid hormone T3 signals tissues to use energy. If the liver is less responsive to T3, resting metabolism may be lower.
  • Changes in LXRβ activity can affect how your body stores and mobilizes fat and how it handles cholesterol and triglycerides.
  • Insulin resistance can develop when metabolism and lipid handling are altered, raising risk for metabolic syndrome.
  • Metabolic health interacts with male reproductive health. Healthy metabolism supports testosterone balance, sperm production, and overall fertility.

Practical steps to support thyroid and metabolic health

Regardless of genetic variation, lifestyle and nutrition strongly influence thyroid and metabolic function. Below are evidence-informed, practical recommendations to support metabolic health and thyroid function.

Diet

  • Adopt a Mediterranean-style eating pattern: plenty of vegetables, fruits, legumes, whole grains, nuts, seeds, and fatty fish.
  • Include fatty fish like salmon, mackerel, sardines, or plant sources of omega-3s. Aim for at least two fish meals per week or discuss supplements with your provider.
  • Prioritize fiber and whole foods to support healthy weight and blood lipids.
  • Limit highly processed foods, sugar-sweetened beverages, and excessive refined carbohydrates, which can worsen insulin resistance and triglycerides.

Key nutrients to check

  • Selenium: supports thyroid hormone metabolism and antioxidant defenses.
  • Zinc: needed for thyroid hormone production and hormone receptor function.
  • Iodine: required to make thyroid hormones. Be cautious with excess intake.
  • Vitamin D: low levels are linked with metabolic dysfunction and reduced male reproductive health.
  • Omega-3 fatty acids: support lipid balance, inflammation control, and metabolic health.

Exercise

  • Combine aerobic exercise and resistance training. Aerobic work improves insulin sensitivity and cardiovascular health. Resistance training supports muscle mass and metabolic rate.
  • Aim for most days of the week with a mix of moderate-intensity cardio and at least two strength sessions per week.

Lifestyle and environment

  • Avoid endocrine disrupting chemicals where possible. Reduce use of plastics for food storage and avoid heating food in plastic containers.
  • Limit exposure to household chemicals and choose fragrance-free personal care products when possible.
  • Manage sleep and stress. Poor sleep and chronic stress can worsen metabolic and hormonal balance.

Monitoring and tests to consider

  • Basic thyroid panel: TSH, free T4, and free T3 to evaluate thyroid function.
  • Fasting lipid panel: total cholesterol, LDL, HDL, and triglycerides.
  • Fasting glucose and insulin or hemoglobin A1c to assess blood sugar regulation.
  • Vitamin D, selenium, zinc, and iodine status as clinically appropriate.
Genetic interpretation: 2 effect alleles (GG) — reduced LXRβ activity

If you have the GG genotype for rs17373080, you carry two copies of the effect allele. This variant is associated with decreased activity of Liver X receptor beta in the liver. Lower LXRβ activity can reduce the liver's sensitivity to thyroid hormone T3, which may lower basal metabolic rate and make weight management more challenging. People with this genotype also often show a higher predisposition to elevated cholesterol, high triglycerides, and insulin resistance.

Practical recommendations

  • Follow a Mediterranean-style diet with emphasis on omega-3 rich fish and plant-based whole foods.
  • Ensure adequate intake of selenium, zinc, iodine, and vitamin D through diet or supplements after discussing with your provider.
  • Prioritize regular combined aerobic and resistance exercise to boost metabolic rate and insulin sensitivity.
  • Monitor fasting lipids, fasting glucose or HbA1c, and a thyroid panel periodically to detect early changes.
  • Reduce exposure to endocrine disruptors by minimizing plastic food contact and choosing safer personal care and household products.
Genetic interpretation: 1 effect allele (CG) — moderately reduced LXRβ activity

If you have the CG genotype for rs17373080, you carry one copy of the effect allele. This is associated with decreased NR1H2 transcription activity in the liver. You may experience a modest reduction in liver sensitivity to T3. That change can contribute to a slightly lower basal metabolic rate, increased difficulty maintaining or losing weight, and a higher tendency toward elevated cholesterol, raised triglycerides, and some insulin resistance. Reduced LXRβ activity may also partially blunt T3-driven activation of brown adipose tissue, which plays a role in heat production and metabolic rate.

Practical recommendations

  • Adopt a Mediterranean-style eating plan with emphasis on vegetables, whole grains, legumes, nuts, and fatty fish.
  • Maintain consistent exercise that includes both aerobic activity and strength training to support muscle mass and metabolic health.
  • Assess and support micronutrients that influence thyroid and metabolic function, including selenium, zinc, iodine, vitamin D, and omega-3s.
  • Keep routine labs for thyroid function, lipids, and glucose regulation, especially if you gain weight, have unusual fatigue, or have family history of metabolic disease.
  • Limit exposure to common endocrine disruptors and prioritize good sleep and stress management.
Genetic interpretation: 0 effect alleles (CC) — typical LXRβ function

If you have the CC genotype for rs17373080, you carry two copies of the non-effect allele. This genotype is associated with normal NR1H2 (LXRβ) function in the liver. Your liver should support standard activation of thyroid hormone T3, which helps maintain a healthy metabolic rate and efficient fat metabolism. With this genotype, your genetic foundation for maintaining weight, healthy cholesterol, and insulin sensitivity is typical.

Practical recommendations

  • Continue a Mediterranean-style diet rich in fruits, vegetables, whole grains, fish, nuts, and healthy fats.
  • Keep regular physical activity with aerobic and strength training components.
  • Maintain adequate intake of selenium, zinc, iodine, vitamin D, and omega-3s through diet or supplements as appropriate.
  • Minimize exposure to endocrine disruptors and monitor thyroid and metabolic labs as part of routine health care.

How to use this information

This genetic information highlights tendencies, not certainties. Lifestyle, diet, sleep, stress, environmental exposures, and other genes also shape your metabolic and thyroid health. Use the recommendations above to build a plan that supports your metabolism and reproductive health. Track changes over time with your healthcare provider and adjust interventions based on labs, symptoms, and clinical guidance.

PlexusDx does not provide medical advice. This information is educational and intended to help you understand how NR1H2 genetic variation may relate to thyroid and metabolic health. Always consult with your healthcare provider before starting or changing diet, supplements, or medical care. Your provider can interpret genetic results in the full context of your health history, current medications, and laboratory testing.