Opportunistic Detection of Phytosterolaemia during Genetic Testing for FH: Case Series and Contextual Review.

BACKGROUND: Homozygous phytosterolaemia, is a rare autosomal recessive disorder which lead to severely elevated plasma levels of plant phytosterols causing an increased risk of coronary artery disease (CAD) and mimics the clinical presentation of familial hypercholesterolaemia(FH). Integration of the genetic variants for homozygous phytosterolaemia into the genetic panel for FH in clinical practice likely increases the detection of milder genetic forms of phytosterolaemia, of which the implications to clinical practice including cascade testing remain unclear. RESULTS: We report three families with pathogenic loss-of-function variants in ABCG5 and/or ABCG8, in which probands were identified incidentally when genetically testing them for FH. The proband of the first family was a 35-year-old man with a homozygous ABCG5 loss-of-function variant (c.1336C > T, p.Arg446*) causing severe phytosterolaemia and premature CAD on cardiac imaging; his younger brother was heterozygous for the same variant with mildly elevated phytosterol levels. The second family included 2 sisters (31 and 29-year-old) with digenic variants in ABCG5 (c.1336C > T, p.Arg446*) and ABCG8 (c.1269G > T, p.Glu423Asp with uncertain significance) with moderately elevated plasma phytosterol levels and premature CAD on cardiac imaging. The third family referred to a 68-year-old man and his 44-year-old daughter who were both heterozygous for a pathogenic ABCG5 variant (c.1166G > A, p.Arg389His), had mild phytosterolaemia and CAD on cardiac imaging. Treatment with ezetimibe alone or in combination with colesevelam reduced elevated plasma sitosterol and campesterol concentrations by 30 to 80%. CONCLUSION: Phytosterolaemia is specific genetic disorder that can mimic FH, cause premature atherosclerosis, and require specific pharmacotherapy. Cascade testing for pathogenic ABCG5/G8 variants can lead to earlier detection and treatment of affected family members.

Elevated remnant cholesterol and non-HDL cholesterol concentrations from real-world laboratory results: a cross-sectional study in Southeast Asians.

Introduction: Triglyceride-rich remnant lipoproteins (TRLs) are considered atherogenic due to the presence of remnant cholesterol, which is transported by apolipoprotein B. In clinical practice, the concentration of TRLs can be estimated by calculating remnant cholesterol or non-HDL cholesterol levels. Aim: This study aims to investigate the proportion of patients who have low LDL cholesterol (LDL-C) concentration but elevated remnant cholesterol concentration, stratified by the presence of hypertriglyceridaemia and ethnicity, using real-world hospital data. Our secondary aim is to investigate the proportion of patients with elevated non-HDL cholesterol levels using guideline-recommended goals. Methods: A 2-year retrospective study was conducted at a single centre, analyzing lipid blood tests of all patients, including directly measured LDL-C. Fasting for blood tests was not mandatory. Results: The study included a total of 21,605 consecutive patients with plasma lipid profiles analyzed in our hospital laboratory. The median age was 61 years. In patients with ASCVD (n = 14,704), 23.7% had an LDL-C level of <1.8 mmol/L, 11.3% had elevated remnant cholesterol concentrations at ≥0.65 mmol/L, and 48.8% were at the non-high-density lipoprotein cholesterol (non-HDL-C) goal (<2.6 mmol/L). Among patients diagnosed with atherosclerotic cardiovascular disease (ASCVD) with LDL-C levels of <1.8 mmol/L (n = 3,484), only 11.9% had high levels of remnant cholesterol, but 96% of the ASCVD patients also achieved the recommended non-HDL-C target of <2.6 mmol/L. When the LDL-C level was <1.8 mmol/L, the mean concentration of remnant cholesterol was 0.214 mmol/L when the triglyceride level was <1.7 mmol/L (n = 3,380), vs. 0.70 mmol/L when the triglyceride level was elevated (n = 724), p < 0.001. Among patients with a triglyceride level of ≥1.7 mmol/L and an LDL-C level of <.8 mmol/L, there were 254 patients with elevated remnant cholesterol concentration and 71 patients with suboptimal non-HDL levels. Malays had a higher mean remnant cholesterol concentration compared with both Chinese and Indians across all LDL-C levels, particularly in the presence of hypertriglyceridaemia. Conclusions: An elevated remnant cholesterol concentration of >0.65 mmol/L was present in 11% of all patients. The current guideline-recommended non-HDL-C goal, which uses a 0.8 mmol/L estimate of remnant cholesterol concentration, was achieved in >92% of patients, suggesting that it is unlikely to be clinically useful for the majority of our patient population except where there is concomitant hypertriglyceridaemia. Further studies are needed to establish the appropriate non-HDL-C goal or calculated remnant cholesterol concentration, paired with the LDL-C goal or otherwise, in a Southeast Asian population.

Prolonged Hypokalemia and Delayed Diagnosis of Primary Aldosteronism: Clinical Course and Risk Factors.

CONTEXT: Primary aldosteronism (PA) is a common cause of hypertension (HT). However, diagnosis is often delayed, leading to poorer clinical outcomes. Hypokalemia with HT is characteristic of PA, and is an indication for screening. OBJECTIVE: We evaluated if patients with PA had prolonged hypokalemia before diagnosis, the subsequent biochemical/clinical control, and factors associated with delayed diagnosis. METHODS: Our study included all PA patients with hypokalemia diagnosed between 2001 and 2022. Delayed diagnosis was defined as duration of hypokalemia of more than 1 year from first occurrence to first evaluation by a PA specialist. Patients were reassessed post adrenalectomy using the Primary Aldosteronism Surgery Outcomes criteria. We performed multivariable analysis to assess for factors associated with delayed diagnosis. RESULTS: Among 240 patients with PA who presented with hypokalemia, 122 (51%) patients had delayed diagnosis, with prolonged hypokalemia of median duration 4.5 years (range, 2.4-7.5 years). Patients with delayed diagnosis were older, had longer duration of HT, higher pill burden, lower renal function, and more prevalent cardiovascular disease. Factors associated with delayed diagnosis included older age, presence of hyperlipidemia, and less severe hypokalemia (serum potassium >3.0 mmol/L). Compared to patients with early diagnosis, a lower proportion of those with delayed diagnosis underwent adrenal vein sampling (73% vs 58%) (P < .05). Sixty of 118 (50.8%) nondelayed, and 39 of 122 (32.0%) patients with delayed diagnosis, underwent surgery. CONCLUSION: Despite manifestation of hypokalemia, many patients with PA fail to be promptly screened. Greater emphasis in HT guidelines, and efforts to improve awareness of PA among primary care physicians, are urgently needed.

Clinical and imaging features of women with polygenic partial lipodystrophy: a case series.

BACKGROUND: Familial partial lipodystrophy (FPLD) is an inherited disorder of white adipose tissue that causes premature cardiometabolic disease. There is no clear diagnostic criteria for FPLD, and this may explain the under-detection of this condition. AIM: This pilot study aimed to describe the clinical features of women with FPLD and to explore the value of adipose tissue measurements that could be useful in diagnosis. METHODS: In 8 women with FPLD and 4 controls, skinfold measurements, DXA and whole-body MRI were undertaken. RESULTS: Whole genome sequencing was negative for monogenic metabolic causes, but polygenic scores for partial lipodystrophy were elevated in keeping with FPLD type 1. The mean age of diagnosis of DM was 31 years in the FPLD group. Compared with controls, the FPLD group had increased HOMA-IR (10.3 vs 2.9, p = 0.028) and lower mean thigh skinfold thickness (19.5 mm vs 48.2 mm, p = 0.008). The FPLD group had lower percentage of leg fat and an increased ratio of trunk to leg fat percentage on DXA. By MRI, the FPLD group had decreased subcutaneous adipose tissue (SAT) volume in the femoral and calf regions (p < 0.01); abdominal SAT, visceral adipose tissue, and femoral and calf muscle volumes were not different from controls. CONCLUSION: Women with FPLD1 in Singapore have significant loss of adipose but not muscle tissue in lower limbs and have early onset of diabetes. Reduced thigh skinfold, and increased ratio of trunk to leg fat percentage on DXA are potentially clinically useful markers to identify FPLD1.

Undiagnosed cardiovascular risk factors including elevated lipoprotein(a) in patients with ischaemic heart disease.

Objectives: This study aims to investigate the prevalence of undiagnosed cardiovascular risk factors in patients with ischaemic heart disease (IHD). Methods: We assessed the prevalence of previously undiagnosed cardiovascular risk factors, including elevated lipoprotein(a) [Lp(a)], among consenting patients with IHD who were admitted to hospital. Clinical information, including dietary history, from patients with newly diagnosed IHD and known IHD were compared. Results: Of the 555 patients, 82.3% were males and 48.5% of Chinese ethnicity. Overall, 13.3% were newly diagnosed with hypertension, 14.8% with hypercholesterolemia, and 5% with type 2 diabetes (T2DM). Patients with newly diagnosed IHD, compared to those with known IHD, had a higher prevalence of new diagnoses of hypercholesterolemia (29.1% vs. 2.0%, p < 0.001), hypertension (24.5% vs. 3.4%, p < 0.001) and T2DM (7.3% vs. 3.1%, p = 0.023). Active smoking was prevalent in 28.3% of patients, and higher in newly diagnosed IHD (34.1% vs. 23.2%, p = 0.005). Elevated Lp(a) of ≥120 nmol/L was detected in 15.6% of all patients, none of whom were previously diagnosed. Dietary habits of >50% of patients in both groups did not meet national recommendations for fruits, vegetables, wholegrain and oily fish intake. However, patients with known IHD had a more regular omega-3 supplement intake (23.4% vs. 10.3%, p = 0.024). Conclusion: Increased detection efforts is necessary to diagnose chronic metabolic diseases (hypertension, hypercholesterolemia, T2DM) especially among patients at high risk for IHD. Cardiovascular risk factors, in particular elevated Lp(a), smoking, and suboptimal dietary intake in patients with IHD deserve further attention.

Comparison of existing methods of low-density lipoprotein cholesterol estimation in patients with type 2 diabetes mellitus.

Introduction: Elevated low-density lipoprotein cholesterol (LDL-C) is an important risk factor for atherosclerotic cardiovascular disease (ASCVD). Direct LDL-C measurement is not widely performed. LDL-C is routinely calculated using the Friedewald equation (FLDL), which is inaccurate at high triglyceride (TG) or low LDL-C levels. We aimed to compare this routine method with other estimation methods in patients with type 2 diabetes mellitus (T2DM), who typically have elevated TG levels and ASCVD risk. Method: We performed a retrospective cohort study on T2DM patients from a multi-institutional diabetes registry in Singapore from 2013 to 2020. LDL-C values estimated by the equations: FLDL, Martin/Hopkins (MLDL) and Sampson (SLDL) were compared using measures of agreement and correlation. Subgroup analysis comparing estimated LDL-C with directly measured LDL-C (DLDL) was conducted in patients from a single institution. Estimated LDL-C was considered discordant if LDL-C was <1.8mmol/L for the index equation and ≥1.8mmol/L for the comparator. Results: A total of 154,877 patients were included in the final analysis, and 11,475 patients in the subgroup analysis. All 3 equations demonstrated strong overall correlation and goodness-of-fit. Discordance was 4.21% for FLDL-SLDL and 6.55% for FLDL-MLDL. In the subgroup analysis, discordance was 21.57% for DLDL-FLDL, 17.31% for DLDL-SLDL and 14.44% for DLDL-MLDL. All discordance rates increased at TG levels >4.5mmol/L. Conclusion: We demonstrated strong correlations between newer methods of LDL-C estimation, FLDL, and DLDL. At higher TG concentrations, no equation performed well. The Martin/Hopkins equation had the least discordance with DLDL, and may minimise misclassification compared with the FLDL and SLDL.

Torsion of the wandering spleen and pancreatic tail precipitating diabetic ketoacidosis in a patient with Prader Willi Syndrome: A case report / Journal of the ASEAN Federation of Endocrine Societies

@#Prader Willi Syndrome (PWS) includes complex endocrinological issues because of the hypothalamic and pituitary dysfunction which include obesity and diabetes, as well as behavioural issues. Other important aspects of PWS, such as hepatosplenomegaly are sometimes neglected. We present a case of diabetic ketoacidosis precipitated by torsion of a wandering spleen in a 22-year-old woman with PWS and type 2 diabetes mellitus. The pancreatic tail was involved in the torsion leading to hyperamylasaemia and pancreatitis. The splenic torsion and pancreatitis were initially treated conservatively with resolution of symptoms. A year later, she had another 2 episodes of severe abdominal pain due to worsening splenic torsion which subsided with conservative management. She subsequently underwent an elective splenectomy which revealed an enlarged and wandering spleen, with 720 degrees torsion of the long splenic pedicle.