Clinical and outcome comparison of genetically positive vs. negative patients in a large cohort of suspected familial hypocalciuric hypercalcemia.

OBJECTIVE: Biochemical suspicion of familial hypocalciuric hypercalcemia (FHH) might provide with a negative (FHH-negative) or positive (FHH-positive) genetic result. Understanding the differences between both groups may refine the identification of those with a positive genetic evaluation, aid management decisions and prospective surveillance. We aimed to compare FHH-positive and FHH-negative patients, and to identify predictive variables for FHH-positive cases. DESIGN: Retrospective, national multi-centre study of patients with suspected FHH and genetic testing of the CASR, AP2S1 and GNA11 genes. METHODS: Clinical, biochemical, radiological and treatment data were collected. We established a prediction model for the identification of FHH-positive cases by logistic regression analysis and area under the ROC curve (AUROC) was estimated. RESULTS: We included 66 index cases, of which 30 (45.5%) had a pathogenic variant. FHH-positive cases were younger (p = 0.029), reported more frequently a positive family history (p < 0.001), presented higher magnesium (p < 0.001) and lower parathormone levels (p < 0.001) and were less often treated for hypercalcemia (p = 0.017) in comparison to FHH-negative cases. Magnesium levels showed the highest AUROC (0.825, 95%CI: 0.709-0.941). The multivariate analysis revealed that family history and magnesium levels were independent predictors of a positive genetic result. The predictive model showed an AUROC of 0.909 (95%CI: 0.826-0.991). CONCLUSIONS: The combination of magnesium and a positive family history offered a good diagnostic accuracy to predict a positive genetic result. Therefore, the inclusion of magnesium measurement in the routine evaluation of patients with suspected FHH might provide insight into the identification of a positive genetic result of any of the CaSR-related genes.

Impaired hypoglycaemia awareness in early pregnancy increases risk of severe hypoglycaemia in the mid-long term postpartum irrespective of breastfeeding status in women with type 1 diabetes.

INTRODUCTION: Information regarding the postpartum period in women with type 1 diabetes (T1D) is scarce. We aim to evaluate the relation of impaired hypoglycaemia awareness (IAH) in early pregnancy and breastfeeding status (its presence and duration) with severe postpartum hypoglycaemia (SH). MATERIALS AND METHODS: Retrospective cohort study of women with T1D followed during pregnancy between 2012 and 2019. Data on SH were recorded before and during pregnancy. IAH was evaluated at the first antenatal visit. Data on breastfeeding and the long-term postpartum period were collected by questionnaire and from medical records. RESULTS: A total of 89 women with T1D were included with a median follow-up after pregnancy of 19.2 [8.7-30.5] months. Twenty-eight (32%) women had IAH at the first antenatal visit. At discharge, 74 (83%) started breastfeeding during a median of 8 [4.4-15] months. A total of 18 (22%) women experienced ≥1 SH during postpartum. The incidence of SH significantly increased from pregestational to the gestational and post-partum period (0.09, 0.15 and 0.25 episodes/patient-year, respectively). Postpartum SH rates were comparable in breastfeeding and non-breastfeeding women (21.4% vs. 25%, respectively, p>0.05). Clarke test score at the first antenatal visit was associated with postpartum SH (for each 1-point increase: OR 1.53; 95% CI, 1.06-2.21) adjusted for confounders. No other diabetes and pregnancy-related variables were identified as predictors of SH in this period. CONCLUSIONS: SH are common in the long-term postpartum period independently of breastfeeding. Assessing IAH in early pregnancy could identify those at an increased risk of SH in the postpartum period.

Changes in physical activity habits in subjects with type 1 diabetes: A comparative study 10 years apart.

INTRODUCTION: Physical activity (PA) is highly recommended in type 1 diabetes (T1D). Few studies have reported the amount of PA performed by individuals with T1D in their daily life, and there is no information about changes over time. MATERIAL AND METHODS: Cross-sectional study in patients with T1D from a referral hospital recruited in two different periods: data from the Biobank registers from 2009 and data from patients attending visits at the hospital in 2019, on a consecutive basis. Data included clinical characteristics and the PA assessment through the International Physical Activity Questionnaire-short form (IPAQ-SF). RESULTS: In 2019, participants with T1D (n=135) reported a lower sedentary lifestyle and greater levels of high PA compared to subjects with T1D (n=355) from 10 years earlier (6.7% vs. 14.1% sedentariness, p=0.015; and 52.6% vs. 25.4% of high PA, p<0.001, respectively). Similar results were identified when the groups were divided according to sex. Both groups presented similar distribution by sex (women, 54% vs. 55%), age (40 vs. 39 years old), years with diabetes (20 vs. 18 years), BMI (25 vs. 24kg/m2) and glycated haemoglobin (7.5% vs. 7.5%, respectively; p>0.05 for all comparisons). Sex and age groups were not determinant for sedentary lifestyle in the different years studied. Analysing all the 490 participants, there was an inverse correlation of age with sitting hours (p=0.024, r=-0.102), total METs (p<0.001, r=-0.146) and HbA1c (p=0.038, r=-0.097). No correlations were found between PA and HbA1c or BMI. CONCLUSIONS: The findings indicate that PA has significantly increased in subjects with T1D over the last 10 years. Future studies are needed to assess whether these healthier habits translate into better outcomes in this high-risk population.

Addition of intermittently scanned continuous glucose monitoring to standard care in a cohort of pregnant women with type 1 diabetes: effect on glycaemic control and pregnancy outcomes.

AIMS/HYPOTHESIS: The aim of this study was to assess whether the addition of intermittently scanned continuous glucose monitoring (isCGM) to standard care (self-monitoring of blood glucose [SMBG] alone) improves glycaemic control and pregnancy outcomes in women with type 1 diabetes and multiple daily injections. METHODS: This was a multicentre observational cohort study of 300 pregnant women with type 1 diabetes in Spain, including 168 women using SMBG (standard care) and 132 women using isCGM in addition to standard care. In addition to HbA1c, the time in range (TIR), time below range (TBR) and time above range (TAR) with regard to the pregnancy glucose target range (3.5-7.8 mmol/l) were also evaluated in women using isCGM. Logistic regression models were performed for adverse pregnancy outcomes adjusted for baseline maternal characteristics and centre. RESULTS: The isCGM group had a lower median HbA1c in the second trimester than the SMBG group (41.0 [IQR 35.5-46.4] vs 43.2 [IQR 37.7-47.5] mmol/mol, 5.9% [IQR 5.4-6.4%] vs 6.1% [IQR 5.6-6.5%]; p=0.034), with no differences between the groups in the other trimesters (SMBG vs isCGM: first trimester 47.5 [IQR 42.1-54.1] vs 45.9 [IQR 39.9-51.9] mmol/mol, 6.5% [IQR 6.0-7.1%] vs 6.4% [IQR 5.8-6.9%]; third trimester 43.2 [IQR 39.9-47.5] vs 43.2 [IQR 39.9-47.5] mmol/mol, 6.1% [IQR 5.8-6.5%] vs 6.1% [IQR 5.7-6.5%]). The whole cohort showed a slight increase in HbA1c from the second to the third trimester, with a significantly higher rise in the isCGM group than in the SMBG group (median difference 2.2 vs 1.1 mmol/mol [0.2% vs 0.1%]; p=0.033). Regarding neonatal outcomes, newborns of women using isCGM were more likely to have neonatal hypoglycaemia than newborns of non-sensor users (27.4% vs 19.1%; ORadjusted 2.20 [95% CI 1.14, 4.30]), whereas there were no differences between the groups in large-for-gestational-age (LGA) infants (40.6% vs 45.1%; ORadjusted 0.73 [95% CI 0.42, 1.25]), Caesarean section (57.6% vs 48.8%; ORadjusted 1.33 [95% CI 0.78, 2.27]) or prematurity (27.3% vs 24.8%; ORadjusted 1.05 [95% CI 0.55, 1.99]) in the adjusted models. A sensitivity analysis in pregnancies without LGA infants or prematurity also showed that the use of isCGM was associated with a higher risk of neonatal hypoglycaemia (non-LGA: ORadjusted 2.63 [95% CI 1.01, 6.91]; non-prematurity: ORadjusted 2.52 [95% CI 1.12, 5.67]). For isCGM users, the risk of delivering an LGA infant was associated with TIR, TAR and TBR in the second trimester in the logistic regression analysis. CONCLUSIONS/INTERPRETATION: isCGM use provided an initial improvement in glycaemic control that was not sustained. Furthermore, offspring of isCGM users were more likely to have neonatal hypoglycaemia, with similar rates of macrosomia and prematurity to those of women receiving standard care.

Cardiovascular Risk Associated With Gender Affirming Hormone Therapy in Transgender Population.

Transgender men and women represent about 0.6 -1.1%% of the general population. Gender affirming hormone therapy (GAHT) helps ameliorate gender dysphoria and promote well-being. However, these treatments' cardiovascular (CV) effects are difficult to evaluate due to the limited number of extensive longitudinal studies focused on CV outcomes in this population. Furthermore, these studies are mainly observational and difficult to interpret due to a variety of hormone regimens and observation periods, together with possible bias by confounding factors (comorbidities, estrogen types, smoking, alcohol abuse, HIV infection). In addition, the introduction of GAHT at increasingly earlier ages, even before the full development of the secondary sexual characteristics, could lead to long-term changes in CV risk compared to current data. This review examines the impact of GAHT in the transgender population on CV outcomes and surrogate markers of CV health. Furthermore, we review available data on changes in DNA methylation or RNA transcription induced by GAHT that may translate into changes in metabolic parameters that could increase CV risk.

Acute Limb Ischemia Secondary to Native Artery Occlusion: Results of a Contemporary Case Series.

BACKGROUND: The treatment of acute limb ischemia (ALI) has barely changed over the last years. However, the progressive implementation of anticoagulants, antiplatelet agents or statins within the population might have modified the profile and prognosis of patients suffering an ALI. The aim of this study was to evaluate the current results of the management of ALI secondary to a native artery occlusion. METHODS: Retrospective study of 220 consecutive patients (mean age 78 years; 49% male) was conducted between 2007 and 2015. ALI secondary to trauma or grafts/stents occlusions were excluded. Statistical analysis was performed with logistic regression. RESULTS: A total of 141 cases (64.1%) were attributed to embolism and 79 (35.9%) to acute arterial thrombosis. Peripheral neuro-ischemic impairment occurred in 135 patients (61.4%), being severe in 42 (19.1%). ALI treatment included anticoagulation (n = 27; 12.3%), regional fibrinolysis (n = 2; 1%), embolectomy/thrombectomy (n = 129; 58.6%), angioplasty/stenting (n = 8; 3.6%), bypass (n = 47; 21.3%) or direct major limb amputation (n = 7; 3.2%). Limb salvage and survival rates at 30/90 days were 95%/95% and 82.3%/74.1%, respectively. Independent risk factors for major amputation were diabetes, severe neuro-ischemic impairment, acute arterial thrombosis and treatment delay >1 day after vascular consultation. In addition, age, chronic peripheral arterial disease, any neuro-ischemic impairment and a hospitalization for any other reason simultaneous to the ALI were independently associated with mortality. CONCLUSIONS: Regardless of excellent limb salvage rates, patients currently suffering from an ALI are, when compared to previous studies, older than before and with an increased rate of mortality. Risk factors do not appear to be modifiable once the ALI appears so prevention strategies should be aimed to avoid the episode.

Germline Mutations in FAN1 Cause Hereditary Colorectal Cancer by Impairing DNA Repair.

Identification of genes associated with hereditary cancers facilitates management of patients with family histories of cancer. We performed exome sequencing of DNA from 3 individuals from a family with colorectal cancer who met the Amsterdam criteria for risk of hereditary nonpolyposis colorectal cancer. These individuals had mismatch repair-proficient tumors and each carried nonsense variant in the FANCD2/FANCI-associated nuclease 1 gene (FAN1), which encodes a nuclease involved in DNA inter-strand cross-link repair. We sequenced FAN1 in 176 additional families with histories of colorectal cancer and performed in vitro functional analyses of the mutant forms of FAN1 identified. We detected FAN1 mutations in approximately 3% of families who met the Amsterdam criteria and had mismatch repair-proficient cancers with no previously associated mutations. These findings link colorectal cancer predisposition to the Fanconi anemia DNA repair pathway, supporting the connection between genome integrity and cancer risk.

Longer telomeres are associated with cancer risk in MMR-proficient hereditary non-polyposis colorectal cancer.

Aberrant telomere length measured in blood has been associated with increased risk of several cancer types. In the field of hereditary non-polyposis colorectal cancer (CRC), and more particularly in Lynch syndrome, caused by germline mutations in the mismatch repair (MMR) genes, we recently found that cancer-affected MMR gene mutation carriers had shorter telomeres and more pronounced shortening of telomere length with age than controls and unaffected MMR gene mutation carriers. Here we evaluate blood telomere length in MMR-proficient hereditary non-polyposis CRC, i.e. familial CRC type X (fCRC-X). A total of 57 cancer-affected and 57 cancer-free individuals from 34 Amsterdam-positive fCRC-X families were analyzed and compared to the data previously published on 144 cancer-affected and 100 cancer-free MMR gene mutation carriers, and 234 controls. Relative telomere length was measured using a monochrome multiplex quantitative PCR method, following strict measures to avoid sources of bias and adjusting by age. Despite the retrospective nature of our study, the results show that longer telomeres associate with cancer risk in fCRC-X, thus identifying different patterns of telomere length according to the status of the MMR system.

New insights into POLE and POLD1 germline mutations in familial colorectal cancer and polyposis.

Germline mutations in DNA polymerase ɛ (POLE) and δ (POLD1) have been recently identified in families with multiple colorectal adenomas and colorectal cancer (CRC). All reported cases carried POLE c.1270C>G (p.Leu424Val) or POLD1 c.1433G>A (p.Ser478Asn) mutations. Due to the scarcity of cases reported so far, an accurate clinical phenotype has not been defined. We aimed to assess the prevalence of these recurrent mutations in unexplained familial and early-onset CRC and polyposis, and to add additional information to define the clinical characteristics of mutated cases. A total of 858 familial/early onset CRC and polyposis patients were studied: 581 familial and early-onset CRC cases without mismatch repair (MMR) deficiency, 86 cases with MMR deficiency and 191 polyposis cases. Mutation screening was performed by KASPar genotyping assays and/or Sanger sequencing of the involved exons. POLE p.L424V was identified in a 28-year-old polyposis and CRC patient, as a de novo mutation. None of the 858 cases studied carried POLD1 p.S478N. A new mutation, POLD1 c.1421T>C (p.Leu474Pro), was identified in a mismatch repair proficient Amsterdam II family. Its pathogenicity was supported by cosegregation in the family, in silico predictions, and previously published yeast assays. POLE and POLD1 mutations explain a fraction of familial CRC and polyposis. Sequencing the proofreading domains of POLE and POLD1 should be considered in routine genetic diagnostics. Until additional evidence is gathered, POLE and POLD1 genetic testing should not be restricted to polyposis cases, and the presence of de novo mutations, considered.

GALNT12 is not a major contributor of familial colorectal cancer type X.

Previous evidence indicates that mutations in the GALNT12 gene might cause a fraction of the unexplained familial colorectal cancer (CRC) cases: GALNT12 is located in 9q22-33, in close proximity to a CRC linkage peak; and germline missense variants that reduce the enzymatic activity of the protein have been identified in CRC patients, some of them with familial CRC history. We hypothesized that mutations in GALNT12 might explain part of the high-risk families grouped as familial CRC type X (fCRC-X), that is, Amsterdam-positive families with mismatch repair proficient tumors. We sequenced the coding regions of the gene in 103 probands of fCRC-X families, finding no functionally relevant mutations. Our results rule out GALNT12 as a major high CRC susceptibility gene. Additional studies are required to provide further evidence about its role as a moderate/low susceptibility gene in familial aggregation of cancer.

Telomere length and genetic anticipation in Lynch syndrome.

Telomere length variation has been associated with increased risk of several types of tumors, and telomere shortening, with genetic anticipation in a number of genetic diseases including hereditary cancer syndromes. No conclusive studies have been performed for Lynch syndrome, a hereditary colorectal cancer syndrome caused by germline mutations in the DNA mismatch repair genes. Here we evaluate telomere length in Lynch syndrome, both as a cancer risk factor and as a mechanism associated with anticipation in the age of cancer onset observed in successive generations of Lynch syndrome families. Leukocyte telomere length was measured in 244 mismatch repair gene mutation carriers from 96 Lynch syndrome families and in 234 controls using a monochrome multiplex quantitative PCR method. Cancer-affected mutation carriers showed significantly shorter telomeres than cancer-free mutation carriers. In addition, cancer-affected carriers showed the most pronounced shortening of telomere length with age, compared with unaffected carriers. The anticipation in the age of cancer onset observed in successive generations was not associated with telomere shortening, although, interestingly, all mother-son pairs showed telomere shortening. In conclusion, cancer-affected mismatch repair gene mutation carriers have distinct telomere-length pattern and dynamics. However, anticipation in the age of onset is not explained by telomere shortening. Pending further study, our findings suggest that telomere attrition might explain the previously reported dependence of cancer risk on the parent-of-origin of mismatch repair gene mutations.

Genetic variant in the telomerase gene modifies cancer risk in Lynch syndrome.

Lynch syndrome (LS) is an inherited cancer-predisposing disorder caused by germline mutations in the mismatch repair (MMR) genes. The high variability in individual cancer risk observed among LS patients suggests the existence of modifying factors. Identifying genetic modifiers of risk could help implement personalized surveillance programs based on predicted cancer risks. Here we evaluate the role of the telomerase (hTERT) rs2075786 SNP as a cancer-risk modifier in LS, studying 255 and 675 MMR gene mutation carriers from Spain and the Netherlands, respectively. The study of the Spanish sample revealed that the minor allele (A) confers increased cancer risk at an early age. The analysis of the Dutch sample confirmed the association of the A allele, especially in homozygosity, with increased cancer risk in mutation carriers under the age of 45 (relative riskLSca<45_AA=2.90; 95% confidence interval=1.02-8.26). Rs2075786 is associated with colorectal cancer (CRC) risk neither in the general population nor in non-Lynch CRC families. In silico studies predicted that the SNP causes the disruption of a transcription binding site for a retinoid receptor, retinoid X receptor alpha, probably causing early telomerase activation and therefore accelerated carcinogenesis. Notably, cancer-affected LS patients with the AA genotype have shorter telomeres than those with GG. In conclusion, MMR gene mutation carriers with hTERT rs2075786 are at high risk to develop a LS-related tumor at an early age. Cancer-preventive measures and stricter cancer surveillance at early ages might help prevent or early detect cancer in these mutation carriers.