Evaluation of adverse clinical outcomes in patients with inflammatory bowel disease receiving different sequences of first- and second-line biologic treatments: findings from ROTARY.

BACKGROUND: Patients with inflammatory bowel disease (IBD) are at risk of developing dysplasia and, subsequently, colorectal cancer (CRC) owing to chronic inflammation. Patients may also experience other severe disease complications, such as hospitalization and surgery. Several biologics are available for the treatment of patients with IBD and some patients require multiple lines of treatment owing to loss of response or tolerability to their prescribed biologic. Previous studies suggest that the choice of initial biologic treatment may impact the outcomes of later treatment lines. In this study, we assessed adverse clinical outcomes in patients with Crohn's disease (CD) or ulcerative colitis (UC) who received different biologic treatment sequences. METHODS: ROTARY part B was a retrospective cohort study using the Optum® Clinical Database that evaluated the incidences of IBD-related hospitalization, IBD-related surgery, dysplasia, CRC, and infections in patients with CD or UC who received two biologics successively. First-line biologics included adalimumab, infliximab, ustekinumab (CD only), and vedolizumab; second-line biologics included infliximab and adalimumab. RESULTS: In patients with CD, the treatment sequence of ustekinumab to infliximab was associated with the highest overall incidences of hospitalization (51.9%), surgery (40.7%), CRC (3.7%), and infection (37.0%). Vedolizumab followed by an anti-tumor necrosis factor alpha (anti-TNFα) treatment was associated with a significantly lower risk of experiencing an adverse medical event (hospitalization, surgery, or infection) than two successive anti-TNFα treatments (odds ratio, 1.526; 95% confidence interval, 1.004-2.320; P < 0.05). In patients with UC, the treatment sequence of vedolizumab to adalimumab resulted in the lowest overall incidence of adverse outcomes (20.3%, 6.3%, 0.0%, 6.3%, and 4.7% for hospitalization, surgery, CRC, dysplasia, and infection, respectively). CONCLUSIONS: We describe differences in adverse clinical outcomes associated with sequencing of biologics in patients with CD or UC and demonstrate favorable results in patients who received vedolizumab as a first-line biologic. These results provide potential guidance to clinicians choosing sequences of biologic treatments in patients with IBD.

Real-world clinical outcomes and healthcare costs in patients with Crohn's disease treated with vedolizumab versus ustekinumab in the United States.

OBJECTIVE: To compare real-world treatment persistence, dose escalation, rates of opportunistic or serious infections, and healthcare costs in patients with Crohn's disease (CD) receiving vedolizumab (VDZ) vs ustekinumab (UST) in the United States. METHODS: A retrospective observational study in adults with CD initiated on VDZ or UST on/after 26 September 2016, was performed using the IBM Truven Health MarketScan databases (1 January 2009-30 September 2018). Rates of treatment persistence, dose escalation, opportunistic or serious infection-related encounters, and healthcare costs per patient per month (PPPM) were evaluated. Entropy balancing was used to balance patient characteristics between cohorts. Event rates were assessed using weighted Kaplan-Meier analyses and compared between cohorts using log-rank tests. Healthcare costs were compared between cohorts using weighted 2-part models. RESULTS: 589 VDZ and 599 UST patients were included (172 [29.2%] and 117 [19.5%] were bio-naïve, respectively). After weighting, baseline characteristics were comparable between cohorts. No significant difference in rates of treatment persistence (12-month: VDZ, 76.5%; UST, 82.1%; p = .17), dose escalation (12-month: VDZ, 29.3%; UST, 32.7%; p = .97), or opportunistic or serious infection-related encounters were observed between VDZ and UST. Total mean healthcare costs were significantly lower for patients treated with VDZ vs UST (mean cost difference = -$5051 PPPM; p < .01). Findings were consistent in bio-naïve patients. CONCLUSIONS: In this real-world study, similar treatment persistence, dose escalation, and rates of opportunistic or serious infections were observed with VDZ- and UST-treated patients with CD. However, VDZ was associated with a significantly lower cost outlay for healthcare systems.

Crohn's disease (CD) causes inflammation in the digestive system. Vedolizumab (VDZ) and ustekinumab (UST) are therapies for patients with CD. Little is known about the clinical outcomes and healthcare costs of VDZ versus UST in the real world in the United States. We used health claims data and found that VDZ and UST had comparable real-world clinical outcomes. After 12 months of treatment, the proportions of patients with CD who stayed on treatment and those who needed to increase therapy dose were similar with VDZ and UST. The rate of infection was also similar between the two groups of patients. However, the monthly healthcare costs were $5051 less for patients treated with VDZ than with UST. This was mainly due to the lower cost of VDZ, which was almost half of that of UST. The lower treatment costs with VDZ may provide substantial savings for the healthcare system and patients specifically. Future cost-effectiveness studies on VDZ and UST are needed to aid treatment selection for patients with CD.

Real-World Persistence of Successive Biologics in Patients With Inflammatory Bowel Disease: Findings From ROTARY.

BACKGROUND: Patients with inflammatory bowel disease (IBD) may receive multiple successive biologic treatments in clinical practice; however, data are limited on the comparative effectiveness of biologics and the impact of treatment sequence on outcomes. METHODS: The ROTARY (Real wOrld ouTcomes Across tReatment sequences in inflammatorY bowel disease patients) study was a retrospective, observational cohort study conducted using data from the Optum Clinical Database between January 1, 2012, and February 29, 2020. Adult patients with Crohn's disease (CD) or ulcerative colitis (UC) who received 2 biologics successively were included. Biologic treatment sequences were analyzed descriptively. Cox proportional hazards models, adjusted for baseline demographics and clinical characteristics, were used to estimate the hazard ratio of switching or discontinuation for each first- and second-line biologic compared with first- and second-line adalimumab, respectively. RESULTS: In total, 4648 patients with IBD (CD, n = 3008; UC, n = 1640) were identified. Most patients received tumor necrosis factor α antagonist (anti-TNFα) treatment followed by another anti-TNFα treatment or vedolizumab. Vedolizumab and infliximab had 39.4% and 34.6% lower rates of switching or discontinuation than adalimumab, respectively, as first-line biologics in patients with CD and 30.8% and 34.3% lower rates as first-line biologics in patients with UC, respectively. Vedolizumab, infliximab, and ustekinumab had 47.2%, 40.0%, and 43.5% lower rates of switching or discontinuation than adalimumab, respectively, as second-line biologics in CD and 56.5%, 43.0%, and 45.6% lower rates as second-line biologics in patients with UC, respectively. CONCLUSIONS: Although anti-TNFα treatments were most commonly prescribed, the adjusted rates of discontinuation for adalimumab as both a first- and second-line biologic were higher than for vedolizumab, infliximab, or ustekinumab.

Patients with inflammatory bowel disease are commonly treated with different sequences of biologics. This study shows that patients who receive adalimumab as their first or second biologic treatment either stop or switch to another biologic at a greater rate than those who are treated with vedolizumab, infliximab, and ustekinumab.

Dose Escalation of Biologics in Biologic-Naïve Patients With Ulcerative Colitis: Outcomes From the ODESSA-UC Study.

Background: Dose escalation of biologics may regain treatment response in patients with ulcerative colitis (UC). However, dose escalation rates and associated outcomes and costs are not well characterized in biologic-naïve patients receiving antitumor necrosis factor-alpha (anti-TNF-α) treatments, such as infliximab or adalimumab or vedolizumab. Methods: ODESSA-UC, a retrospective cohort study investigating dose escalation in patients with UC who had received first-line biologics, used data from IBM MarketScan databases. Adults with UC and ≥1 claim for an index drug (adalimumab, infliximab, or vedolizumab) were eligible. A Cox proportional hazards model was used to evaluate the adjusted rate of dose escalation. Logistic regression was used to evaluate the odds of experiencing adverse outcomes (corticosteroid use, infection, sepsis, or inflammatory bowel disease-related hospitalization) and incurring index drug costs. Results: A year after the start of maintenance, a lower proportion of patients experienced dose escalation with vedolizumab (22.3%) than adalimumab (43.0%). The dose escalation risk was significantly higher for infliximab (hazard ratio [HR], 1.894; 95% confidence interval [CI], 1.486-2.413) and adalimumab (HR, 2.120; 95% CI, 1.680-2.675) than for vedolizumab. The odds of experiencing an adverse outcome after dose escalation were higher for anti-TNF-α treatments than for vedolizumab (odds ratio, 2.052; 95% CI, 1.200-3.507). Index drug costs after dose escalation were lowest for vedolizumab. Conclusions: Patients with UC receiving vedolizumab had a lower risk of dose escalation and lower subsequent costs than patients receiving anti-TNF-α treatments. Our study demonstrates the possible clinical and economic implications of dose escalation.

Practical Primer Addressing Real-World Use Scenarios of Subcutaneous Vedolizumab in Ulcerative Colitis and Crohn's Disease: Post Hoc Analyses of VISIBLE Studies.

Background: Vedolizumab, an anti-α4ß7 integrin approved for intravenous (IV) treatment of moderately to severely active ulcerative colitis (UC) and Crohn's disease (CD), was evaluated as a subcutaneous (SC) formulation in maintenance therapy for UC and CD in phase 3 VISIBLE 1, 2, and open-label extension studies, and recently approved in Europe, Australia, and Canada. Our aim was to evaluate efficacy and safety of IV and SC vedolizumab in clinically relevant UC and CD scenarios. Methods: Post hoc data analyses from VISIBLE trials examined: (1) whether baseline characteristics predict clinical response to 2 vs 3 IV vedolizumab induction doses; (2) efficacy and safety of switching during maintenance vedolizumab IV to SC in patients with UC; (3) vedolizumab SC after treatment interruption of 1-46 weeks; (4) increasing dose frequency of vedolizumab SC from every 2 weeks (Q2W) to every week (QW) after disease worsening. Results: No baseline characteristics were identified as strong predictors of response to 2 vs 3 vedolizumab infusions. Most patients achieved clinical response after 2 or 3 doses of IV vedolizumab maintained with SC treatment. Clinical remission and response rates were maintained in patients transitioned from maintenance vedolizumab IV to SC treatment. Of patients with UC, ≥75% achieved response following resumption after dose interruption. Escalation to QW dosing resulted in ≥45% of patients regaining response after loss while receiving vedolizumab Q2W. Conclusions: Clinical real-world scenarios with vedolizumab SC were reviewed using VISIBLE studies data. Vedolizumab SC provides an additional dosing option for patients with UC and CD.

Comparison of surgery rates in biologic-naïve patients with Crohn's disease treated with vedolizumab or ustekinumab: findings from SOJOURN.

BACKGROUND: Crohn's disease (CD) is a chronic inflammatory bowel disease characterized by relapsing and remitting inflammation that leads to progressive bowel damage. Despite advances in medical treatment for CD, many patients require surgical intervention. Most studies of surgery rates are from patients treated with anti-tumor necrosis factor alpha (anti-TNFα) treatments, with comparatively little data on the surgery rates of patients treated with vedolizumab and ustekinumab. SOJOURN aimed to estimate the hazard rate and incidence of the first CD-related surgery following initiation of treatment with vedolizumab or ustekinumab in biologic-naïve patients with CD. METHODS: SOJOURN was a retrospective, observational cohort study examining administrative claims data from the Optum® Research Database between July 1, 2017 and March 31, 2020. Included participants were adults with a diagnosis of CD and a claim for vedolizumab or ustekinumab (defined as the index treatment) between January 1, 2018 and December 31, 2019, with no claims for a biologic in the 6 months before initiation of this treatment. The variable follow-up started on the day after the index date and continued until whichever came first of discontinuation of the index treatment, surgery event, switching of the index treatment, initiation of combination biologic treatment, disenrollment, or March 31, 2020. The time to the first CD-related surgery on biologic treatment was estimated by Kaplan-Meier analysis. The hazard ratio and incidence rate ratio of CD-related surgery for each treatment cohort was compared using a Cox proportional hazards model and a Poisson regression model, respectively. RESULTS: Of the 1,122 included patients, 578 received vedolizumab and 544 received ustekinumab. After 1 year of the variable follow-up, 7.7% of patients receiving vedolizumab and 11.6% of patients receiving ustekinumab had undergone a CD-related surgery. Vedolizumab was associated with a 34.2% lower hazard rate of surgery (hazard ratio 0.658, 95% confidence interval [CI] 0.436-0.994, p = 0.047) and a 34.5% lower incidence of surgery (rate ratio 0.655, 95% CI 0.434-0.988, p = 0.044) than ustekinumab. CONCLUSIONS: This real-world analysis of biologic-naïve patients with CD suggests that vedolizumab is associated with greater effectiveness in reducing the rate of CD-related surgery than ustekinumab.

Use, Durability, and Risks for Discontinuation of Initial and Subsequent Biologics in a Large Pediatric-Onset IBD Cohort.

BACKGROUND: Biologic medications are recommended for treatment of moderately-to-severely active Crohn disease (CD) or ulcerative colitis (UC) in children. However, many patients require sequential biologic treatment because of nonresponse or loss of response to the initial biologic. METHODS: We analyzed pediatric inflammatory bowel disease (IBD) data from the ImproveCareNow Network registry between May 2006 and September 2016, including time to biologic initiation, choice of first subsequent biologics, biologic durability, and reasons for discontinuation. RESULTS: Of 17,649 patients with IBD [CD: 12,410 (70%); UC: 5239 (30%)], 7585 (43%) were treated with a biologic agent before age 18 (CD: 50%; UC: 25%). Biologic treatment was more likely for CD than UC (odds ratio, 3.0; 95% CI: 2.8-3.2; P < 0.0001). First biologic agents for all patients were anti-tumor necrosis factor agents (88% infliximab, 12% adalimumab). Probability of remaining on the first biologic was significantly higher in CD than UC ( P < 0.0001). First biologics were discontinued because of loss of response (39%), intolerance (23%), and nonresponse (19%). In univariate analysis, factors associated with discontinuation of first and/or second biologics in CD include colonic-only disease, corticosteroid use, upper gastrointestinal tract involvement, and clinical and biochemical markers of severe disease. Biologic durability improved with later induction date. CONCLUSIONS: Treatment with biologic medications is common in pediatric IBD. Patients with CD are more likely to receive biologics, receive biologics earlier in disease course, and remain on the first biologic longer than patients with UC. Multiple factors may predict biologic durability in children with IBD.

Evaluating cost per remission and cost of serious adverse events of advanced therapies for ulcerative colitis.

BACKGROUND: Determining the relative cost-effectiveness between advanced therapeutic options for ulcerative colitis (UC) may optimize resource utilization. We evaluated total cost per response, cost per remission, and cost of safety events for patients with moderately-to-severely active UC after 52 weeks of treatment with advanced therapies at standard dosing. METHODS: An analytic model was developed to estimate costs from the US healthcare system perspective associated with achieving efficacy outcomes and managing safety outcomes for advanced therapies approved for the treatment of UC. Numbers needed to treat (NNT) for response and remission, and numbers needed to harm (NNH) for serious adverse events (SAEs) and serious infections (SIs) were derived from a network meta-analysis of pivotal trials. NNT for induction and maintenance were combined with drug regimen costs to calculate cost per clinical remission. Cost of managing AEs was calculated using NNH for safety outcomes and published costs of treating respective AEs. RESULTS: Costs per remission were $205,240, $249,417, $267,463, $365,050, $579,622, $750,200, and $787,998 for tofacitinib 10 mg, tofacitinib 5 mg, infliximab, vedolizumab, golimumab, adalimumab, and ustekinumab, respectively. Incremental costs of SAEs and SIs collectively were $136,390, $90,333, $31,888, $31,061, $20,049, $12,059, and $0 for tofacitinib 5 mg, golimumab, adalimumab, tofacitinib 10 mg, infliximab, ustekinumab, and vedolizumab (reference), respectively. CONCLUSIONS: Tofacitinib was associated with the lowest cost per response and cost per remission, while vedolizumab had the lowest costs related to SAEs and SIs. Balancing efficacy versus safety is important when evaluating the costs associated with treatment of moderate-to-severe UC.

Impact of COVID-19 on Healthcare Resource Utilisation Among Patients with Inflammatory Bowel Disease in the USA.

BACKGROUND AND AIMS: The impact of the COVID-19 pandemic on patients with inflammatory bowel disease [IBD] is largely unknown. We characterised the impact of COVID-19 on IBD care by conducting an analysis of US health care claims data. METHODS: We obtained de-identified, open-source, health insurance claims data, from January 2019 to December 2020, from the Symphony Health Integrated Dataverse for US adults with IBD, and measured the rates per 1000 patients of five outcomes: colonoscopies; new biologic or small molecule treatment initiations or treatment switches; new biologic or small molecule treatment initiations or treatment switches in patients who had a colonoscopy within the previous 60 days; IBD-related surgeries; and telehealth consultations. RESULTS: For 2019 and 2020, 1.32 million and 1.29 million patients with IBD, respectively, were included in the analysis. In March-April 2020, the rates of colonoscopies [17.39 vs 34.44], new biologic or small molecule treatment initiations or switches in patients who had a colonoscopy within the previous 60 days [0.76 vs 1.18], and IBD-related surgeries [2.33 vs 2.99] per 1000 patients were significantly decreased versus January-February 2020; significant year on year decreases versus 2019 were also observed. Telehealth utilisation increased in March 2020 and remained higher than in 2019 up to December 2020. CONCLUSIONS: Reduction in colonoscopies and subsequent initiation/switching of treatments during the COVID-19 pandemic suggest lost opportunities for therapy optimisation which may have an impact on longer-term patient outcomes. Increased utilisation of telehealth services may have helped address gaps in routine clinical care.

Performance Characteristics of a Clinical Decision Support Tool for Disease Complications in Crohn's Disease.

Background: Patients with Crohn's disease (CD) are at risk of complications. Performance characteristics of a decision support tool assessing the risk of CD complications were evaluated. Methods: CDPATH (formerly called the Personalized Risk and Outcome Prediction Tool [PROSPECT]) was calibrated and validated in 2 cohorts. Tool prediction of disease characteristics was assessed using Cox regression and Harrell's C-statistic. Results: All associations of CD complications and CDPATH components were significant except perianal location. There was a significant association between individualized risk assessment scores and CD complications in both cohorts. Conclusion: CDPATH is validated as a clinical decision support tool for assessing the risk of CD complications.

P042 Early Versus Later Use of Vedolizumab In IBD: Patient Characteristics And Treatment Patterns In The Real World (RALEE).

BACKGROUND: Pivotal trials in inflammatory bowel disease (IBD) demonstrate that earlier use of biologics is associated with greater likelihood of response/remission, but multiple studies have identified that in the real world, biologic treatment is often delayed, thereby limiting optimal effectiveness and increasing likelihood of adverse outcomes. Further assessment of patient, provider, and payor factors that contribute to therapy choice is needed. We assessed utilization of vedolizumab (VDZ) and performed a real-world assessment using administrative datasets. Here, we describe the different treatment patterns and demographics of patients who received VDZ. METHODS: We identified VDZ-treated patients (aged ≥18 years) with Crohn's disease (CD) or ulcerative colitis (UC) in the MarketScan commercial and Medicare claims databases from 2017 to 2019 and included those who had continuous enrollment in the same health plan for ≥12 months prior to their initial IBD diagnostic claim, ≥1 VDZ claim after the initial IBD diagnosis, and continuous enrollment for ≥12 months prior to and after their initial UC or CD diagnosis. Patients exposed to VDZ, anti-TNF, or other biologic therapy in the 12-month pre-index period were excluded. We pre-defined 5 treatment pathways: (1) EARLY VDZ - VDZ within 30 days of first IBD diagnostic claim; (2) DELAYED VDZ 1 - immunomodulators and then switch to VDZ; (3) DELAYED VDZ 2 - corticosteroids with immunomodulators prior to VDZ; (4) DELAYED VDZ 3 - 5-ASA with corticosteroids prior to VDZ; or (5) DELAYED VDZ 4 - 5-ASA with corticosteroids and immunomodulators prior to VDZ. Differences in patient baseline characteristics among these treatment pathways were analyzed descriptively. RESULTS: We identified 136,315 patients with UC and 103,591 with CD, from which 1,342 patients with UC (median age 43 years; 51.0% male; 96.4% commercially insured; 86.4% diagnosed in 2017) and 964 with CD (median age 45 years; 43.6% male; 94.6% commercially insured; 88.6% diagnosed in 2017) received VDZ and met criteria. The proportions of patients by treatment pathway were (UC|CD): EARLY VDZ (6.6%|9.6%); DELAYED VDZ 1 (7.5%|19.0%); DELAYED VDZ 2 (14.8%|36.8%); DELAYED VDZ 3 (37.6%|19.0%); DELAYED VDZ 4 (33.4%|15.6%). Among patients with UC, EARLY VDZ vs DELAYED VDZ cohorts had median age of 40 vs 44 years and proportion of men of 46.1% vs 51.4%. Among patients with CD, EARLY VDZ vs DELAYED VDZ had median age of 43 vs 45 years and proportion of men of 39.8%% vs 43.9%. For both indications, no meaningful differences among treatment groups by geographic region, payor type (i.e., commercial vs Medicare), and year of diagnosis were observed. CONCLUSION: In this administrative real-world dataset, fewer than 10% of patients with IBD were treated with VDZ within 30 days of diagnosis, and these patients were more likely to be younger and women. These findings are distinct from guidelines suggesting VDZ may be used earlier, or due to its safety profile, preferentially in older patients at higher risk for infection. Further analyses of safety and effectiveness outcomes are underway.

Correction: Vitamin D status in pediatric irritable bowel syndrome.

[This corrects the article DOI: 10.1371/journal.pone.0172183.].

Vitamin D status in pediatric irritable bowel syndrome.

IMPORTANCE: Irritable bowel syndrome (IBS) is associated with significant morbidity in children and adolescents, and the therapeutic efficacy of available treatment options is limited. The role of vitamin D supplementation in pediatric IBS is unclear as the vitamin D status of pediatric patients with IBS is unknown. Equally, the relationship of vitamin D status with psychosomatic symptoms in children and adolescents is unclear. AIM: To characterize the vitamin D status of pediatric patients with IBS using a case-control study design. HYPOTHESIS: Serum 25-hydroxyvitamin D [25(OH)D] concentration will be similar between patients with IBS and controls. SUBJECTS AND METHODS: A retrospective case-controlled study of 116 controls (age 14.6 ± 4.3 y), female (n = 67; 58%) and 55 subjects with IBS (age 16.5 ± 3.1y), female (n = 44; 80%). Overweight was defined as BMI of ≥85th but <95th percentile, and obesity as BMI ≥95th percentile. Vitamin D deficiency was defined as 25(OH)D of <50 nmol/L, while seasons of vitamin D draw were categorized as summer, winter, spring, and fall. Major psychosomatic manifestations included in the analysis were depression, anxiety, and migraine. RESULTS: More than 50% of IBS subjects had vitamin D deficiency at a cut-off point of <50 nmol/L (53% vs. 27%, p = 0.001); and >90% of IBS subjects had vitamin D deficiency at a cut-off point of <75 nmol/L (93% vs. 75%, p = 0.006). IBS subjects had significantly lower mean 25(OH)D: 53.2 ± 15.8 nmol/L vs. 65.2 ± 28.0 nmol/L, p = 0.003; and albumin: 6.2 ± 0.6 vs. 6.5 ± 0.6 µmol/L, p = 0.0.01. IBS subjects with migraine had significantly lower mean 25(OH)D concentration compared to controls (p = 0.01). BMI z-score was similar between the controls and IBS subjects (0.5 ± 1.4 vs. 1.2 ± 2.9, p = 0.11). CONCLUSIONS: Pediatric patients with IBS had significantly lower 25(OH)D concentration compared to controls despite having similar mean BMI values as controls. Only 7% of the children and adolescents with IBS were vitamin D sufficient, and >50% of the subjects with IBS had vitamin D deficiency. This is a much higher prevalence of vitamin D deficiency compared to IBD and other malabsorption syndromes. Monitoring for vitamin D deficiency should be part of the routine care for patients with IBS. Randomized control trials are warranted to determine the role of adjunctive vitamin D therapy in pediatric IBS.

Lactose intolerance: lack of evidence for short stature or vitamin D deficiency in prepubertal children.

BACKGROUND: The health consequences of lactose intolerance (LI) are unclear. AIMS: To investigate the effects of LI on stature and vitamin D status. HYPOTHESES: LI subjects will have similar heights and vitamin D status as controls. SUBJECTS AND METHODS: Prepubertal children of ages 3-12 years with LI (n=38, age 8.61 ± 3.08y, male/female 19/19) were compared to healthy, age- and gender-matched controls (n=49, age 7.95±2.64, male/female 28/21). INCLUSION CRITERIA: prepubertal status (boys: testicular volume <3cc; girls: Tanner 1 breasts), diagnosis of LI by hydrogen breath test, and no history of calcium or vitamin D supplementation. Vitamin D deficiency was defined as 25-hydroxyvitamin D [25(OH)D] <50 nmol/L. Gender-adjusted midparental target height (MPTH) z-score was calculated using NCHS data for 18 year-old adults. Data were expressed as mean ± SD. RESULTS: There was no significant difference in 25(OH)D between the LI and non-LI subjects (60.1±21.1, vs. 65.4 ± 26.1 nmol/L, p = 0.29). Upon stratification into normal weight (BMI <85(th) percentile) vs. overweight/obese (BMI ≥85(th) percentile), the normal weight controls had significantly higher 25(OH)D level than both the normal weight LI children (78.3 ± 32.6 vs. 62.9 ± 23.2, p = 0.025), and the overweight/obese LI children (78.3±32.6 vs. 55.3±16.5, p = 0.004). Secondly, there was no overall difference in height z-score between the LI children and controls. The normal weight LI patients had similar height as normal controls (-0.46 ± 0.89 vs. -0.71 ± 1.67, p = 0.53), while the overweight/obese LI group was taller than the normal weight controls (0.36 ± 1.41 vs. -0.71 ± 1.67, p = 0.049), and of similar height as the overweight/obese controls (0.36 ± 1.41 vs. 0.87 ± 1.45, p = 0.28). MPTH z-score was similar between the groups. CONCLUSION: Short stature and vitamin D deficiency are not features of LI in prepubertal children.

Severe obesity and diabetes insipidus in a patient with PCSK1 deficiency.

Non-synonymous mutations affecting both alleles of PCSK1 (proprotein convertase 1/3) are associated with obesity and impaired prohormone processing. We report a proband who was compound heterozygous for a maternally inherited frameshift mutation and a paternally inherited 474kb deletion that encompasses PCSK1, representing a novel genetic mechanism underlying this phenotype. Although pro-vasopressin is not a known physiological substrate of PCSK1, the development of central diabetes insipidus in this proband suggests that PCSK1 deficiency can be associated with impaired osmoregulation.