Applicability of Martin-Hopkins formula and comparison with Friedewald formula for estimated low-density lipoprotein cholesterol in e_COR study population.

INTRODUCTION: Low-density lipoprotein cholesterol (LDL) is essential in managing cardiovascular disease risk. Since 1972, the Friedewald formula has been used to estimate LDL concentration, although with some limitations. In 2013, Martin et al. proposed a similar but more accurate formula for calculating LDL. AIM: To assess the applicability of the new formula, which we have named the Martin-Hopkins formula, in the Portuguese population and compare it with the Friedewald formula using direct LDL. METHODS: Cross-sectional study, including 1689 participants from the e_COR study. We applied the Martin-Hopkins and Friedewald formulas for estimated LDL (LDL-M and LDL-F). The Friedewald formula was not applied in 12 cases due to triglycerides ≥400mg/dL. Direct LDL was measured and the accepted significance level was p<0.05. RESULTS: Of the total subjects, 50.2% were male and had a median age of 51 (34) years. LDL-D was 117.0 (44.0) mg/dL, LDL-M was 114.6 (43.7) mg/dL and LDL-F was 113.8 (43.2) mg/dL. The Spearman coefficient (ρ) between LDL-M/LDL-D was 0.987 and between LDL-F/LDL-D was 0.983, p=0.001. This strong correlation was maintained in the group with diabetes (LDL-M/LDL-D ρ=0.987; LDL-F/LDL-D ρ=0.978, p=0.001) and hypertriglyceridemia (LDL-M/LDL-D ρ=0.983; LDL-F/LDL-D ρ=0.982, p=0.001). In terms of agreement, the highest value of κ=0.90 was obtained for LDL-M when LDL-D <100mg/dL. CONCLUSION: The Martin-Hopkins formula performed well and had good applicability, showing superiority in relation to the Friedewald formula, especially for LDL-D values <100mg/dL, diabetes, and hypertriglyceridemia.

Applicability of Martin-Hopkins formula and comparison with Friedewald formula for estimated low-density lipoprotein cholesterol in e_COR study population. / Aplicabilidade da fórmula Martin­Hopkins e comparação com a fórmula Friedewald na estimativa do colesterol LDL na população do estudo e_COR.

INTRODUCTION: Low-density lipoprotein cholesterol (LDL) is essential in managing cardiovascular disease risk. Since 1972, the Friedewald formula has been used to estimate LDL concentration, although with some limitations. In 2013, Martin et al. proposed a similar but more accurate formula for calculating LDL. AIM: To assess the applicability of the new formula, which we have named the Martin-Hopkins formula, in the Portuguese population and compare it with the Friedewald formula using direct LDL. MATERIAL AND METHODS: Cross-sectional study, including 1689 participants from the e_COR study. We applied the Martin-Hopkins and Friedewald formulas for estimated LDL (LDL-M and LDL-F). The Friedewald formula was not applied in 12 cases due to triglycerides ≥400mg/dL. Direct LDL was measured and the accepted significance level was p<0.05. RESULTS: Of the total subjects, 50.2% were male and had a median age of 51 (34) years. LDL-D was 117.0 (44.0) mg/dL, LDL-M was 114.6 (43.7) mg/dL and LDL-F was 113.8 (43.2) mg/dL. The Spearman coefficient (ρ) between LDL-M/LDL-D was 0.987 and between LDL-F/LDL-D was 0.983, p=0.001. This strong correlation was maintained in the group with diabetes (LDL-M/LDL-D ρ=0.987; LDL-F/LDL-D ρ=0.978, p=0.001) and hypertriglyceridemia (LDL-M/LDL-D ρ=0.983; LDL-F/LDL-D ρ=0.982, p=0.001). In terms of agreement, the highest value of κ=0.90 was obtained for LDL-M when LDL-D <100 mg/dL. CONCLUSION: The Martin-Hopkins formula performed well and had good applicability, showing superiority in relation to the Friedewald formula, especially for LDL-D values <100 mg/dL, diabetes, and hypertriglyceridemia.

Graves' disease and recurrence in ectopic thyroid tissue after total thyroidectomy.

We report a case of a 46-year-old woman who presented with a midline neck mass 2 years after total thyroidectomy for Graves' disease. Despite levothyroxine treatment withdrawal, she remained biochemically with subclinical hyperthyroidism. Her thyroid stimulating hormone receptor antibodies were consistently elevated. Neck ultrasonography revealed an infrahyoid solid nodule and pertechnetate scintigraphy confirmed an increased uptake at the same level, without any uptake in the thyroid bed. Treatment with methimazole 5 mg/day was initiated with clinical improvement and achievement of euthyroidism. After that, she received 10 mCi of radioactive iodine. Since then, she experienced regression of the neck mass and is doing well on a replacement dose of levothyroxine. Recurrence of Graves' disease in ectopic thyroid following total thyroidectomy is extremely rare. This diagnose should be considered in patients who underwent total thyroidectomy and remained with thyrotoxicosis despite decreasing the levothyroxine dose.

Ovarian Leydig cell tumor and postmenopausal hirsutism with signs of virilisation.

A 71-year-old woman was referred to the endocrinology clinic to investigate postmenopausal hirsutism with 10 years of evolution. She had history of regular menses and menopause with 50 years old. Physical examination showed a male pattern facies, deepening of the voice, androgenic alopecia and hirsutism with a score of 23 according to the modified Ferriman-Gallwey scale. Testosterone and androstenedione were increased. Transvaginal ultrasound, abdominal and pelvic CT showed uterine fibroids with no pathological findings in the adrenals or ovaries. Since she had postmenopausal vaginal bleeding, uterine fibroids and suspicion of an ovarian source for her hyperandrogenism, total hysterectomy and bilateral oophorectomy were performed. Histopathological diagnosis was a Leydig cell tumour located in left ovary and endometrial carcinoma. Improvement of hirsutism was started to notice 1 month after the surgery and she was referred to the oncology clinic for adjuvant treatment.

Case of newly diagnosed bilateral anorchia in a 42-year-old male patient.

A 42-year-old African man presented with hypogonadic phenotypical features, including gynoid body distribution, gynaecomastia, absent facial and truncal hair and micropenis. He denied ever experiencing development of male secondary sex characteristics. Endocrine testing revealed hypergonadotropic hypogonadism and undetectable AMH. Human chorionic gonadotropin (hCG) stimulation test failed to increase testosterone levels. Peripheral blood karyotype was 46, XY. Clinical examination and abdominal/pelvic/scrotal ultrasound and MRI failed to identify any testicular structures/remnants. Given the clinical course and the biochemical-radiological presentation, the diagnosis of bilateral anorchia was made (after more than four decades of its probable onset), and surgical exploration was decided against. The patient was subsequently started on monthly intramuscular testosterone experiencing progressive normal virilisation.