from the division director
Dr. Katie Larson Ode has been named director of the Clinical Core component of the University of Iowa’s Center for Gene Therapy of Cystic Fibrosis. The NIH grant funding for this project was just renewed. Her core will support maintenance and growth of a Cystic Fibrosis biobank which will obtain/provide clinical samples from/to researchers in cystic fibrosis for translational projects. Congratulations to Dr. Larson Ode on your excellent work.
By invitation, Dr. Lauren Kanner has been installed as the Workshops Co-Chair on the Program Committee for the North American Society for Pediatric and Adolescent Gynecology (NASPAG) 2021 Annual Clinical & Research Meeting. In this role, she will help plan and set the agenda for the workshops to occur at this national meeting. She also is now the pediatric endocrine liason for the Fellow Research Consortium of NASPAG. She remains a member of the NASPAG education committee, a role she has maintained since April 2018. Thanks to Dr. Kanner for her hard work in this important area.
As the COVID-19 pandemic began impacting the region in March 2020, it quickly became apparent that the pandemic would impact our Division of Pediatric Endocrinology & Diabetes ability to provide healthcare and would adversely impact many of the children and families for whom we provide care. In response to this arising situation, the Leona M. And Harry B. Helmsley Charitable Trust issued a call for grant proposals aimed at providing local solutions relating to type 1 diabetes care. Dr. Tansey answered this call, writing a proposal to aid with delivery of healthcare for those with type 1 diabetes cared for by our clinic. The goal of the Helmsley program is to “improve the lives of all people living with type 1 diabetes (T1D). Working closely with key players across the T1D ecosystem – patients, physicians, caregivers, researchers, government agencies, funders, pharmaceutical companies, device makers, insurers, and community organizations – we seek to improve care and ultimately prevent the disease.” I am pleased to announce that the proposal created by Dr. Tansey has been approved and funded, as of today. The funds will help our team provide services to our patients with type 1 diabetes, through improved telemedicine education opportunities, and will help provide services to those whom have been directly affected by COVID-19. My deepest gratitude to Dr. Tansey for taking the initiative and rapidly helping answer the challenges imposed by the COVID-19 pandemic.
Post by
Andrew Norris, MD PhD
Director, Pediatric Endocrinology & Diabetes
University of Iowa Stead Family Children’s Hospital
I am excited to report that the Iowa newborn screening program will begin using age-adjusted TSH cut-offs starting March 30, 2020. The purpose is to better screen newborns for congenital hypothyroidism, which is a condition that if untreated leads to profound deficiencies in brain development and body growth. The cutoff changes are expected to improve both the specificity and sensitivity of the screen. Otherwise, in general, there will be no change in workflow as involves endocrinologists and primary care providers. Only the cutoffs are changing. Despite these improvements, the newborn screen remains only a screening test and should not be used as a quantitative test to examine an infant in whom you suspect a thyroid abnormality.
click each to open/close
We remain available 24/7:
Please know that we are here for our patients. We and other centers have noticed that patients are often sicker than in the past when they come for medical care, presumably because they have delayed seeking care out of fear of contracting COVID-19. Importantly, please know that our medical center remains one of the safest places. All visitors are screened, including by temperature scanning cameras, and all staff maintain strict precautions. If you have questions or concerns about managing your endocrine condition, please contact us by phone/email/fax. If you are ill and might benefit from endocrine advice, we will work hard with you over the phone to help keep you from needing to come to the hospital. As of May 4, we have carefully re-opened our outpatient clinic for routine visits, in accordance with policies set by the State of Iowa. Additionally, we can conduct selected routine visits not requiring physical examination via video-chat. Contact us and we will help you arrange a clinic visit. Further information can be found at our official clinical website.
A reassuring note:
The healthcare community is learning more about the effects of COVID-19 on specific patients. You may have read that diabetes is a risk factor for severe COVID-19. Please know however that this data regards adults, mainly older adults. On March 25th, our European colleagues reported their impression that pediatric-aged patients with diabetes are not at increased risk of severe COVID-19. Likewise, initial data reports from the US have not mentioned diabetes as a pediatric-aged risk factor. On May 29, a peer-reviewed French scientific article reported similar findings. See this blog post for more details. It would be reasonable to assume the same is likely true for pediatric-aged patients with various endocrine disease, though we have yet to see any data. In any case, it remains important to be careful with your diabetes and endocrine medications. For youth with diabetes, aim to control your blood sugars as best possible, make sure to take your long-acting insulin / keep your insulin pump in good working order. The reason to keep your blood sugars in range as best possible is that persons with diabetes have a higher risk of needing to be hospitalized with COVID if their blood sugar have been running higher (see our review of this data). For youth with adrenal insufficiency, make sure to take your prescribed hydrocortisone or other steroids, and give stress dose steroids if ill etc as instructed. Keep your prescriptions up. Be sure to minimize exposures, practice social distancing, frequent hand washing, etc. See our hospital COVID-19 website for additional information.
COVID-19 increases risk of DKA:
Data has now been published showing that many persons with type 1 diabetes who develop COVID-19 will develop diabetic ketoacidosis (DKA). Our summary of the study can be found here (link). If you or your loved one has type 1 diabetes, and develops symptoms of COVID-19, be sure to contact your diabetes doctor to help provide advice on how to prevent DKA. Fluids, carbohydrates, ketone checks, and extra insulin are very important in this regard. We remain on call 24×7 to assist.
Adrenal insufficiency may increase COVID-19 risk:
Several endocrine sources have published opinions suggesting that adrenal insufficiency may predispose persons to severe COVID-19. Our summary of these opinions can be found here (link). If you or your loved one has adrenal insufficiency, it might be important to minimize COVID-19 exposures, wear protective masks, practice social distancing and frequent hand washing, etc. If you have questions or concerns, we are happy to discuss. If you think you have developed COVID-19, please know that we remain on call 24×7 to assist.
“When these tumors occur in children, the manifestations are often different than in adults.“
Post by
Andrew Norris, MD PhD
Director, Pediatric Endocrinology & Diabetes
University of Iowa Stead Family Children’s Hospital
A concise review of hormone-secreting pituitary tumors and their clinical syndromes appears in today’s New England Journal of Medicine. The article starts by noting that hormone secreting pituitary adenomas account for ~15% of all intercranial tumors. Although the article is informative and well written, it largely omits the characteristics of these disorders in childhood. When these tumors occur in children, the manifestations are often different than in adults. Below I have tabulated the anterior pituitary hormones that can be oversecreted by pituitary adenomas, and their common related childhood syndromes / symptoms. The table is listed in order of prevalence, from occasional to exceedingly rare (just a few case reports ever). Some of the symptoms of these conditions are common and non-specific (e.g. headache) and usually do not indicate a pituitary adenoma. Other symptoms almost always warrant an endocrine workup, especially growth failure, galactorrhea, precocious puberty, pubertal failure, gigantism, and acromegaly. On the flip side of hormone-secreting adenomas are pituitary adenomas that do not secrete hormones. Even though such adenomas do not secrete hormones, they eventually can lead to symptoms once their size impinges on local function. These manifestations can include visual field defects, headache, deficiency of pituitary hormones though prolactin can be modestly elevated due to pituitary stalk compression. Importantly, hormone secreting adenomas can also lead to these size-related effects as well.
| Hormone oversecreted | Childhood manifestations |
| Prolactin (prevalence ~1/10,000) | Menstrual disturbance (girls) Galactorrhea (girls) Gynecomastia (boys) Pubertal delay/failure (boys) |
| ACTH (incidence <1/million/yr) | Weight gain Growth failure Striae Hypertension Amenorrhea (girls) Hirsutism (girls) |
| Growth hormone (rare) | Gigantism Acromegaly |
| TSH (exceedingly rare) | Hyperthyroidism Headache |
| LH, FSH (exceedingly rare) | Precocious puberty |
Post by
Andrew Norris, MD PhD
Director, Pediatric Endocrinology & Diabetes
University of Iowa Stead Family Children’s Hospital
Diabetic ketoacidosis (DKA) is a diabetes emergency that can result in death when not detected quickly and treated in a timely fashion. DKA is most commonly caused by taking insufficient insulin, especially forgetting to take long acting insulin, or taking insufficient extra insulin during illness. Children and adolescents with diabetes are at particular risk to develop DKA. For reasons that are not fully understood, rates of DKA are increasing (see this 2018 commentary in Diabetes Care). Insulin degludec is an ultra-long-acting insulin analog. Its duration of action exceeds 30 hours, which is longer than other current long acting insulin types. For this reason, it has been postulated that use of insulin degludec might reduce DKA risk when compared to other long-acting insulin analogs, especially among those who occasionally forget to take their long acting insulin. However, evidence has mixed. A study in 2015 Pediatric Diabetes found a reduction in ketosis when comparing children on degludec versus insulin detemir (note: the study was funded by Novo Nordisk, the maker of both degludec and detemir). This is the least meaningful of all possible comparisons since insulin detemir is the shortest acting of current long acting insulins. This 2015 European regulatory document presents an analysis of DKA rates from a company trial comparing insulin degludec versus detemir, finding no differences. A study published in 2018 Diabetes Therapy examined 42 adults who switched to insulin degludec found fewer DKA events after the switch, though the study was not powered for statistical conclusions (again this study was funded by Novo Nordisk). This month, work published in Feb 2020 Hormone Research in Paediatrics reports a retrospective study of 35 adolescents with DKA who switched from insulin glargine (in its most common “U100” formulation) to insulin degludec. The adolescents experienced significantly fewer DKA episodes after the switch. This exciting data suggests that degludec may indeed help reduce risks of DKA in youth at risk. Although these are encouraging, the retrospective nature of the study and lack of a control group prevents firm conclusions. In general, DKA rates are expected to subside with time in adolescents as they mature and better learn to prevent this unpleasant complication. A control group of adolescents who did not switch to degludec would have helped interpret the results. Degludec has other benefits, especially less hypoglycemia compared to other long acting insulins (see this 2018 meta-analysis).
“with the advent of techniques to strengthen brain regions, such as transcranial magnetic stimulation, might this type of research help guide possible interventions?” –Andrew Norris
Dr. Tsalikian and collaborators across the country have been studying brain cognitive function in children with and without type 1 diabetes. In a study just published in PLOS Medicine, they report interesting differences. They used functional magnetic imaging resonance (fMRI) to measure activation in various brain locations while the children were given tasks. Compared to children without diabetes, those with type 1 diabetes exhibited two differences. One of the observed changes was impaired control of a region towards the back of the brain and this impairment typically leads to diminished task performance. In contrast, there was enhanced activation of a region towards the front of the brain involved in executive control. It appears that these two changes balanced each other, in that the two groups had similar task performance. Simply put, it appears that the brains of children with type 1 diabetes are able to compensate for impairments presumably induced by long-term exposure to high blood sugars. More study is needed to understand this latter point in particular, for example would the pattern normalize if the blood sugars were held to the normal range during the study? Furthermore, more study is needed to understand the broader implications of this work, for example might these or related changes contribute to the increased risk of depression in persons with diabetes? Finally, with the advent of techniques to strengthen brain regions, such as transcranial magnetic stimulation, might this type of research help delineate important interventions? Also involved in the study from our Division were Dr. Tansey, Julie Coffey, Joanne Cabbage, Sara Salamati, and Rachel Bisbee.
Post by
Andrew Norris, MD PhD
Director, Pediatric Endocrinology & Diabetes
University of Iowa Stead Family Children’s Hospital
There has long been some controversy regarding what blood glucose threshold should be used in newborns to guide when to initiate therapeutic intervention. This is an important concern, because sufficiently severe hypoglycemia can cause damage to the brain. However, it has been difficult to ascertain what degrees of hypoglycemia induce risk. This week the New England Journal of Medicine has published results from a new study focused on this question. Infants were randomized to receive intervention once blood glucose was under 47 (conventional cutoff) or 36 mg/dL. Psychomotor development was assessed at 18 months of age. The study found that outcomes in the more liberal cutoff group (36 mg/dL) were not any different from the conventional group. This suggests that the more liberal cutoff may be reasonable to use in clinical practice. An important caveat from the perspective of pediatric endocrinology is that this study pertains to healthy infants who do not have any specific endocrinologic or metabolic disorder. In fact the authors “emphasize the need for a higher target glucose concentration in newborns who have persistent hypoglycemia due to endocrine or metabolic disorders“. –Andrew Norris
“Thus, these data implicate that cystic fibrosis induces defects in glucagon secretion leading to hypoglycemia risk. The association with pancreatic insufficiency suggests a link to pancreatic exocrine disease.” –Andrew Norris
Post by
Andrew Norris, MD PhD
Director, Pediatric Endocrinology & Diabetes
University of Iowa Stead Family Children’s Hospital
Results from an important recent clinical study of hypoglycemia in patients with cystic fibrosis (CF) are now available. The study was conducted at the University of Washington and headed by preeminent diabetes physiologist Dr. Steven Kahn. Non-diabetic adults with cystic fibrosis were challenged with a 3-hour 75-gram frequently-sampled oral glucose tolerance test.
Half (14/27) of the subjects experienced hypoglycemia during the test. The glycemic pattern during the test was similar between these two groups until 135 minutes and thereafter, when the hypoglycemia group diverged downward. Those who exhibited hypoglycemia were more likely to be pancreatic insufficient. Importantly, those with hypoglycemia had lower plasma insulin & C-peptide levels. Modeling suggest that insulin sensitivity was greater in the subjects with hypoglycemia, accounting for the lower insulin levels. Importantly though, the “oral disposition index” did not differ between the two groups. This indicates that the amount of insulin secreted between the two groups would expected to have the same actions on lowering glucose when accounting for insulin sensitivity. Perhaps one could argue that the “oral disposition index” should have been lower in the hypoglycemia group, but in fact there was a trend towards lower values in this group (P=0.16). Plasma GLP-1 and GIP did not differ between the groups. In the hypoglycemia group, plasma epinephrine rose in the hypoglycemia group, albeit modestly. Cortisol did not rise, though it is not clear how many patients reached the lower blood glucose thresholds needed to trigger cortisol secretion. Growth hormone rose in some but not all patients. Perhaps most importantly, glucagon did not rise with hypoglycemia and did not differ at any point between the two groups.
These results suggest an impairment in counterregulatory response in patients with CF and hypoglycemia. Typically, the threshold for glucagon secretion occurs at less severe degrees of hypoglycemia than for other counterregulatory responses (see this nice review from Elizabeth Seaquist). Furthermore, the hypoglycemia in these subjects was mild. Thus, these data implicate that cystic fibrosis induces defects in glucagon secretion leading to hypoglycemia risk. The association with pancreatic insufficiency suggests a link to pancreatic exocrine disease. However, the mechanisms responsible remain to be determined. The manuscript describing these results is now published in the prestigious journal Diabetologia (link to article).