Prevalence of diabetes and pre-diabetes in a cohort of Italian young adults with Williams syndrome

Body mass index variation in adults with Williams syndrome: associations with predicted dietary intake and food behaviors

Background

Dietary intake and body weight are important predictors of long-term health. However, few studies have focused on these topics in adults with genetic syndromes that have associated intellectual disability, such as Williams syndrome (WS).

Objective

In adults with WS, describe predicted dietary intake, food-related problems, and associations between body mass index (BMI) and possible factors contributing to differences in weight status.

Design

In this study of 82 participants (median age of 30 years, range 18-69), we cross sectionally investigated associations between BMI, predicted dietary intakes (Dietary Screener Questionnaire), food-related behaviors (Food-Related Problem Questionnaire), and anxiety (Spence Children's Anxiety Scale). Longitudinal patterns of weight change were further studied in a subset (n = 41).

Results

BMI variation was observed with median BMI of 27.3 kg/m² (range 16.7-55.5 kg/m²). Several components of dietary intake deviated from recommendations in the WS cohort. When compared with WS participants with either normal or overweight BMI, WS participants with obesity had reduced daily intake of fruits and vegetables of 0.15 cup equivalents (P = 0.049), while participants with underweight BMI had reduced daily intake of fruits and vegetables of 0.44 cup equivalents (P = 0.026) and additionally had reduced intake of dietary fiber of 2.12 grams per day (P = 0.019). A one-point increase in the 'preoccupation with food' sub-score was associated with a 0.57 unit increase in BMI (P = 0.16), while a one-point increase in the 'takes and stores food' sub-score was associated with a 0.72 unit increase in BMI. In the longitudinal weight subset, a weight gain group and a weight stable group were identified. The former was associated with increased 'takes and stores food' sub-score but not with dietary intakes.

Conclusion

We observed considerable BMI variability. While few dietary intakes were associated with BMI, increased BMI and weight gain were associated with 'preoccupation with food' and with 'takes and stores food' behavior sub-scores.

Williams-Beuren Syndrome Related Methyltransferase WBSCR27: From Structure to Possible Function

Williams-Beuren syndrome (WBS) is a genetic disorder associated with the hemizygous deletion of several genes in chromosome 7, encoding 26 proteins. Malfunction of these proteins induce multisystemic failure in an organism. While biological functions of most proteins are more or less established, the one of methyltransferase WBSCR27 remains elusive. To find the substrate of methylation catalyzed by WBSCR27 we constructed mouse cell lines with a Wbscr27 gene knockout and studied the obtained cells using several molecular biology and mass spectrometry techniques. We attempted to pinpoint the methylation target among the RNAs and proteins, but in all cases neither a direct substrate has been identified nor the protein partners have been detected. To reveal the nature of the putative methylation substrate we determined the solution structure and studied the conformational dynamic properties of WBSCR27 in apo state and in complex with S-adenosyl-L-homocysteine (SAH). The protein core was found to form a canonical Rossman fold common for Class I methyltransferases. N-terminus of the protein and the β6–β7 loop were disordered in apo-form, but binding of SAH induced the transition of these fragments to a well-formed substrate binding site. Analyzing the structure of this binding site allows us to suggest potential substrates of WBSCR27 methylation to be probed in further research.

Elastic tissue disruption is a major pathogenic factor to human vascular disease

Elastic fibers are essential components of the arterial extracellular matrix. They consist of the protein elastin and an array of microfibrils that support the protein and connect it to the surrounding matrix. The elastin gene encodes tropoelastin, a protein that requires extensive cross-linking to become elastin. Tropoelastin is expressed throughout human life, but its expression levels decrease with age, suggesting that the potential to synthesize elastin persists during lifetime although declines with aging. The initial abnormality documented in human atherosclerosis is fragmentation and loss of the elastic network in the medial layer of the arterial wall, suggesting an imbalance between elastic fiber injury and restoration. Damaged elastic structures are not adequately repaired by synthesis of new elastic elements. Progressive collagen accumulation follows medial elastic fiber disruption and fibrous plaques are formed, but advanced atherosclerosis lesions do not develop in the absence of prior elastic injury. Aging is associated with arterial extracellular matrix anomalies that evoke those present in early atherosclerosis. The reduction of elastic fibers with subsequent collagen accumulation leads to arterial stiffening and intima-media thickening, which are independent predictors of incident hypertension in prospective community-based studies. Arterial stiffening precedes the development of hypertension. The fundamental role of the vascular elastic network to arterial structure and function is emphasized by congenital disorders caused by mutations that disrupt normal elastic fiber production. Molecular changes in the genes coding tropoelastin, lysyl oxidase (tropoelastin cross-linking), and elastin-associated microfibrils, including fibrillin-1, fibulin-4, and fibulin-5 produce severe vascular injury due to absence of functional elastin.

Growth, body composition, and endocrine issues in Williams syndrome

PURPOSE OF REVIEW

Williams syndrome is a multisystem disorder caused by a microdeletion on chromosome 7q. Throughout infancy, childhood, and adulthood, abnormalities in body composition and in multiple endocrine axes may arise for individuals with Williams syndrome. This review describes the current literature regarding growth, body composition, and endocrine issues in Williams syndrome with recommendations for surveillance and management by the endocrinologist, geneticist, or primary care physician.

RECENT FINDINGS

In addition to known abnormalities in stature, calcium metabolism, and thyroid function, individuals with Williams syndrome are increasingly recognized to have low bone mineral density, increased body fat, and decreased muscle mass. Furthermore, recent literature identifies a high prevalence of diabetes and obesity starting in adolescence, and, less commonly, a lipedema phenotype in both male and female individuals. Understanding of the mechanisms by which haploinsufficiency of genes in the Williams syndrome-deleted region contributes to the multisystem phenotype of Williams syndrome continues to evolve.

SUMMARY

Multiple abnormalities in growth, body composition, and endocrine axes may manifest in individuals with Williams syndrome. Individuals with Williams syndrome should have routine surveillance for these issues in either the primary care setting or by an endocrinologist or geneticist.

Psychopharmacology of Williams syndrome: safety, tolerability, and effectiveness

Introduction: Williams syndrome (WS) is a neurogenetic disorder characterized by a hyper-social personality, intellectual disability, and multiple medical co-morbidities. Psychiatric co-morbidities are also common. Since medical co-morbidities are common in this population, the risk-benefit of the use of psychiatric medications must be carefully considered and monitoring for safety and tolerability is needed.Areas covered: We review the cognitive profile and common medical co-morbidities in WS. We then discuss the common presentations of psychiatric disorders and review the available evidence on the use of psychiatric medications in WS. No prospective psychiatric medication trials have been conducted. We highlight the side effect profile of common psychiatric medications as they pertain to WS.Expert opinion: Psychiatric disorders can have a major effect on the quality of life of individuals with WS. The lack of long-term safety data and high likelihood of medical co-morbidities in WS make the judicious use of psychiatric medications more challenging; however, they can play an important role in decreasing distress and improving functioning. We provide recommendations for first- and second-line classes of medications based on our clinical experience and consideration of adverse effect profiles, as well as safety monitoring parameters at baseline and periodically.

Health Care Supervision for Children With Williams Syndrome

This set of recommendations is designed to assist the pediatrician in caring for children with Williams syndrome (WS) who were diagnosed by using clinical features and with chromosome 7 microdeletion confirmed by fluorescence in situ hybridization, chromosome microarray, or multiplex ligation-dependent probe amplification. The recommendations in this report reflect review of the current literature, including previously peer-reviewed and published management suggestions for WS, as well as the consensus of physicians and psychologists with expertise in the care of individuals with WS. These general recommendations for the syndrome do not replace individualized medical assessment and treatment.

Bone involvement and mineral metabolism in Williams' syndrome

CONTEXT

The previous studies suggested a possible increased risk of hypercalcaemia and reduced bone mineral density (BMD) in Williams' syndrome (WS). However, an extensive study regarding bone metabolism has never been performed.

OBJECTIVE

To investigate bone health in young adults with WS.

DESIGN

Cross-sectional study.

SETTINGS

Endocrinology and Metabolic Diseases and Medical Genetic Units.

PATIENTS

29 WS young adults and 29 age- and sex-matched controls.

MAIN OUTCOME MEASURES

In all subjects, calcium, phosphorus, bone alkaline phosphatase (bALP), parathyroid hormone (PTH), 25-hydroxyvitamin D (25OHVitD), osteocalcin (OC), carboxyterminal cross-linking telopeptide of type I collagen (CTX), 24-h urinary calcium and phosphorus, femoral-neck (FN) and lumbar-spine (LS) BMD and vertebral fractures (VFx) were assessed. In 19 patients, serum fibroblast growth factor-23 (FGF23) levels were measured.

RESULTS

WS patients showed lower phosphorus (3.1 ± 0.7 vs 3.8 ± 0.5 mg/dL, p = 0.0001) and TmP/GFR (0.81 ± 0.32 vs 1.06 ± 0.25 mmol/L, p = 0.001), and an increased prevalence (p = 0.005) of hypophosphoremia (34.5 vs 3.4%) and reduced TmP/GFR (37.9 vs 3.4%). Moreover, bALP (26.3 ± 8.5 vs 35.0 ± 8.0 U/L), PTH (24.5 ± 12.6 vs 33.7 ± 10.8 pg/mL), OC (19.4 ± 5.3 vs 24.5 ± 8.7 ng/mL), and FN-BMD (- 0.51 ± 0.32 vs 0.36 ± 0.32) were significantly lower (p < 0.05), while CTX significantly higher (401.2 ± 169.3 vs 322.3 ± 122.4 pg/mL, p < 0.05). Serum and urinary calcium and 25OHVitD levels, LS-BMD and VFx prevalence were comparable. No cases of hypercalcemia and suppressed FGF23 were documented. Patients with low vs normal phosphorus and low vs normal TmP/GFR showed comparable FGF23 levels. FGF23 did not correlate with phosphorus and TmP/GFR values.

CONCLUSIONS

Adult WS patients have reduced TmP/GFR, inappropriately normal FGF23 levels and an uncoupled bone turnover with low femoral BMD.

Glucose and lipid metabolism, bone density, and body composition in individuals with Williams syndrome

OBJECTIVE

We assessed body composition, bone mineral density (BMD), glucose and lipids in Williams syndrome (WS), a rare microdeletion disorder.

DESIGN

Individuals with WS had outpatient assessment at Massachusetts General Hospital. Controls were selected from the National Health and Nutrition Examination Survey (NHANES 2005-2006).

PATIENTS

A total of 22 individuals with WS, each matched by age, sex and race to four NHANES controls.

MEASUREMENTS

Blood sampling, oral glucose tolerance test, dual-energy X-ray absorptiometry scan.

RESULTS

WS and control groups were 59% female and 29 ± 8 years old. Compared to controls, individuals with WS were shorter but had similar body weight, with more fat and less lean mass. Per cent body fat was higher in WS even after adjusting for BMI (+2.1% [95% CI 0.4, 3.9%]). Four WS patients had abnormal lower extremity fat accumulation resembling lipedema. HbA1c (+0.5% [0.2, 0.7]) and 2-hour glucose (+68 mg/dL [44, 93]) were higher in WS vs controls, differences which persisted after adjusting for BMI. Fasting glucose was comparable between groups. LDL (-18 mg/dL [-35, -2]) and triglycerides (-45 mg/dL [-87, -2]) were significantly lower in WS. Whole-body BMD was significantly lower (-0.15 g/cm² [-0.20, -0.11]) in WS, and this remained true controlling for height (-0.06 g/cm² [-0.11, -0.02]). Vitamin D was <30 ng/mL in 81% of those with WS.

CONCLUSIONS

On average, adults with WS have increased fat, decreased lean mass, impaired glucose homeostasis and reduced BMD. Clinical efforts to build muscle and bone mass, and to ensure vitamin D sufficiency, are warranted. Genotype-phenotype research efforts are also warranted.

High prevalence of diabetes mellitus, hypertension and obesity among persons with a recorded diagnosis of intellectual disability or autism spectrum disorder

BACKGROUND

Obesity and lack of physical activity are frequently reported in persons with intellectual disability (ID) or autism spectrum disorder (ASD). We hypothesised a higher prevalence of diabetes and hypertension in this population.

METHOD

We used administrative data for all primary and specialist outpatient and inpatient healthcare consultations for people with at least one recorded diagnosis of diabetes mellitus, hypertension or obesity from 1998 to 2015. Data were drawn from the central administrative database for Stockholm County, Sweden. It was not possible to separate data for type 1 and type 2 diabetes. We stratified 26 988 individuals with IDs or ASD into three groups, with Down syndrome treated separately, and compared these groups with 1 996 140 people from the general population.

RESULTS

Compared with the general population, men and women with ID/ASD had 1.6-3.4-fold higher age-adjusted odds of having a registered diagnosis of obesity or diabetes mellitus, with the exception of diabetes among men with Down syndrome. A registered diagnosis of hypertension was only more common among men with ID/ASD than in the general population.

CONCLUSIONS

Diabetes and blood pressure health screening, along with efforts to prevent development of obesity already in childhood, are necessary for individuals with IDs and ASD. We believe that there is a need for adapted community-based health promotion programmes to ensure more equitable health for these populations.

Impaired glucose metabolism in subjects with the Williams-Beuren syndrome: A five-year follow-up cohort study

Objective

The Williams-Beuren syndrome (WS) is associated with impaired glucose metabolism (IGM) early in adulthood. However, the pathophysiology of IGM remains poorly defined, due to the lack of longitudinal studies investigating the contribution of β-cell dysfunction and impaired insulin sensitivity. This study aimed at assessing incidence of IGM and the underlying mechanisms in WS adults.

Methods

This observational, longitudinal (5-year), cohort study enrolled thirty-one consecutive WS subjects attending a tertiary referral center. An oral glucose tolerance test (OGTT) was performed yearly and used to classify patients as normal or IGM, including impaired fasting glucose (IFG) and/or impaired glucose tolerance (IGT) and diabetes mellitus (DM), and to calculate surrogate measures of insulin secretion and/or sensitivity.

Results

IGM patients were 18 (58.1%, three DM) at baseline and 19 (61.3%, five DM) at end-of-follow-up. However, 13 individuals changed category of glucose homeostasis in both directions during follow-up (8 progressors, 5 regressors) and 18 did not (8 non-progressors, 10 non-regressors). New cases of IGM and DM were 11.1 and 2.53 per 100 persons-year, respectively, and were treated non-pharmacologically. In the whole cohort and, to a higher extent, in progressors, indices of early-phase insulin secretion and insulin sensitivity decreased significantly from baseline to end-of-follow-up, with concurrent reduction of the oral disposition index and insulin secretion-sensitivity index-2 (ISSI-2), compensating insulin secretion for the level of insulin resistance. No baseline measure independently predicted progression, which correlated with change from baseline in ISSI-2. Compared with patients with normal glucose homeostasis, IGT subjects had impaired insulin sensitivity, whereas insulin secretion was reduced only in those with IFG+IGT or DM.

Conclusions

IGM incidence is high in young adults with WS, suggesting the need of early screening and timed intervention. As in classical type 2 diabetes, impaired insulin sensitivity and β-cell dysfunction contribute, in this sequence, to progression to IGM and DM.

Williams-beuren syndrome is a genetic disorder associated with impaired glucose tolerance and diabetes in childhood and adolescence: new insights from a longitudinal study

BACKGROUND

In adults with Williams-Beuren syndrome (WBS), a common endocrine abnormality is type 2 diabetes mellitus (T2DM) or impaired glucose tolerance (IGT). However, few and sporadic data are available in children, adolescents, and young adults with WBS.

AIM

To evaluate the frequency of IGT and T2DM in a cohort of children and young patients with WBS.

PATIENTS AND METHODS

We longitudinally evaluated 27 patients (9 males and 18 females, median age at study onset 13.6 years) with WBS. The median follow-up was 3.6 years. Variables of insulin resistance and β-cell function were evaluated in all subjects using an oral glucose tolerance test. The homeostasis model assessment (HOMA) of insulin resistance and the Matsuda index of insulin sensitivity were calculated. The study of the GCK and HNF1Α genes was performed in patients with glucose metabolism abnormalities. 45 age- and sex-matched healthy subjects and 51 age-, sex- and BMI-matched subjects were recruited as two control groups.

RESULTS

Considering nutritional status, 7 (25.9%) patients were obese, 9 (33.3%) overweight, and 11 (40.8%) normal-weight. One (3.1%) patient had acanthosis nigricans. IGT was diagnosed in 7 (25.9%) WBS patients and T2DM in 3 (11.1%). Considering all WBS patients, the median value of HOMA was 5.23 (range 2.93-14.89; insulin 24.73 ± 14.67 μU/ml; glucose 104.98 ± 16.06 mg/dl). Considering BMI values, HOMA was 11.00 (range 6.53-12.56), 5.64 (range 3.54-7.95), and 4.54 (range 3.21-5.43), and insulin was 34.53 ± 6.84, 22.76 ± 8.91, and 19.47 ± 6.01 μU/ml in obese, overweight, and normal-weight WBS patients, respectively. Comparing the results with the two control groups, WBS patients showed higher insulin values than healthy controls (p < 0.001), but similar values as the BMI-matched control group (p = n.s.). However, WBS patients showed significantly higher values of glycemia (healthy control group, p < 0.001; BMI-matched control group, p < 0.05) and HOMA (healthy control group, p < 0.001; BMI-matched control group, p < 0.05) than the two control groups. Finally, among WBS patients there was a higher number of subjects with IGT and T2DM than among healthy controls (p < 0.0001) and the BMI-matched control group (p = 0.0002).

CONCLUSION

Our data strongly suggest that IGT and T2DM may be frequently discovered in children, adolescents, and young adults with WBS. WBS should be included among the genetic syndromes associated with T2DM. Further studies are necessary to evaluate the etiopathogenesis of this aspect.

Elastin Insufficiency Predisposes Mice to Impaired Glucose Metabolism

Williams-Beuren syndrome is the consequence of a large contiguous-gene deletion on the seventh human chromosome that includes the elastin gene. Elastin is an extracellular matrix protein responsible for the cardiovascular abnormalities associated with Williams’s syndrome, including hypertension and aortic stenosis. A high percentage of individuals with Williams’s syndrome also have impaired glucose tolerance, independent of traditional risk factors for diabetes. Here, we show that murine adipose tissue does assemble elastic fibers; however, isolated elastin insufficiency (Eln^+/−) in mice does not independently influence glucose metabolism or tissue lipid accumulation. Similarly, isolated ApoE deficiency (ApoE^−/−), a model of hyperlipidemia and atherosclerosis, does not impair insulin sensitivity. However, Eln^+/−; ApoE^−/− double mutant mice exhibit notable hyperglycemia, adipocyte hypertrophy, inflammation of adipose tissue, and ectopic lipid accumulation in liver tissue. Further, Eln^+/−; ApoE^−/− mutants have significant impairment of insulin sensitivity by insulin tolerance testing, independent of body weight or diet, suggesting that elastin insufficiency predisposes to metabolic disease in susceptible individuals.