Pejman Cohan

Euglycemic Diabetic Ketoacidosis: A Potential Complication of Treatment With Sodium–Glucose Cotransporter 2 Inhibition

OBJECTIVE Sodium–glucose cotransporter 2 (SGLT-2) inhibitors are the most recently approved antihyperglycemic medications. We sought to describe their association with euglycemic diabetic ketoacidosis (euDKA) in hopes that it will enhance recognition of this potentially life-threatening complication. RESEARCH DESIGN AND METHODS Cases identified incidentally are described. RESULTS We identified 13 episodes of SGLT-2 inhibitor–associated euDKA or ketosis in nine individuals, seven with type 1 diabetes and two with type 2 diabetes, from various practices across the U.S. The absence of significant hyperglycemia in these patients delayed recognition of the emergent nature of the problem by patients and providers. CONCLUSIONS SGLT-2 inhibitors seem to be associated with euglycemic DKA and ketosis, perhaps as a consequence of their noninsulin-dependent glucose clearance, hyperglucagonemia, and volume depletion. Patients with type 1 or type 2 diabetes who experience nausea, vomiting, or malaise or develop a metabolic acidosis in the setting of SGLT-2 inhibitor therapy should be promptly evaluated for the presence of urine and/or serum ketones. SGLT-2 inhibitors should only be used with great caution, extensive counseling, and close monitoring in the setting of type 1 diabetes.

Acute secondary adrenal insufficiency after traumatic brain injury: A prospective study

Objective:To determine the prevalence, time course, clinical characteristics, and effect of adrenal insufficiency (AI) after traumatic brain injury (TBI). Design:Prospective intensive care unit–based cohort study. Setting:Three level 1 trauma centers. Patients:A total of 80 patients with moderate or severe TBI (Glasgow Coma Scale score, 3–13) and 41 trauma patients without TBI (Injury Severity Score, >15) enrolled between June 2002 and November 2003. Measurements:Serum cortisol and adrenocorticotropic hormone levels were drawn twice daily for up to 9 days postinjury; AI was defined as two consecutive cortisols of ≤15 &mgr;g/dL (25th percentile for extracranial trauma patients) or one cortisol of <5 &mgr;g/dL. Principal outcome measures included: injury characteristics, hemodynamic data, usage of vasopressors, metabolic suppressive agents (high-dose pentobarbital and propofol), etomidate, and AI status. Main Results:AI occurred in 42 TBI patients (53%). Adrenocorticotropic hormone levels were lower at the time of AI (median, 18.9 vs. 36.1 pg/mL; p = .0001). Compared with patients without AI, those with AI were younger (p = .01), had higher injury severity (p = .02), had a higher frequency of early ischemic insults (hypotension, hypoxia, severe anemia) (p = .02), and were more likely to have received etomidate (p = .049). Over the acute postinjury period, patients with AI had lower trough mean arterial pressure (p = .001) and greater vasopressor use (p = .047). Mean arterial pressure was lower in the 8 hrs preceding a low (≤15 &mgr;g/dL) cortisol level (p = .003). There was an inverse relationship between cortisol levels and vasopressor use (p = .0005) and between cortisol levels within 24 hrs of injury and etomidate use (p = .002). Use of high-dose propofol and pentobarbital was strongly associated with lower cortisol levels (p < .0001). Conclusions:Approximately 50% of patients with moderate or severe TBI have at least transient AI. Younger age, greater injury severity, early ischemic insults, and the use of etomidate and metabolic suppressive agents are associated with AI. Because lower cortisol levels were associated with lower blood pressure and higher vasopressor use, consideration should be given to monitoring cortisol levels in intubated TBI patients, particularly those receiving high-dose pentobarbital or propofol. A randomized trial of stress-dose hydrocortisone in TBI patients with AI is underway.

CHRONIC HYPOPITUITARISM AFTER TRAUMATIC BRAIN INJURY: RISK ASSESSMENT AND RELATIONSHIP TO OUTCOME

OBJECTIVE Chronic pituitary dysfunction is increasingly recognized as a sequela of traumatic brain injury. We sought to define the incidence, risk factors, and neurobehavioral consequences of chronic hormonal deficiencies after complicated mild, moderate, or severe traumatic brain injury. METHODS Patients aged 14 to 80 years were prospectively enrolled at the time of injury and assessed at 3 and 6 to 9 months after injury for hormonal function and neurobehavioral consequences. Major and minor (subclinical) hormonal deficiencies, including growth hormone deficiency (GHD) and growth hormone insufficiency (GHI), were identified. Acute injury characteristics, neurobehavioral, and quality of life measures were compared in patients with and without major hormonal deficits by the use of multivariate analysis. RESULTS Out of 70 patients (mean age, 32 yr; median Glasgow Coma Scale score, 7; 19% women) tested at 6 to 9 months after injury, 15 (21%) had at least one major hormonal deficiency, 20 (29%) had minor deficiencies, and 30 (43%) had major and/or minor deficiencies. Patients with major deficiencies included 16% with GHD or GHI, 10.5% with hypogonadism, and 1.4% with diabetes insipidus. None of the patients required adrenal or thyroid replacement. At 6 to 9 months after injury, patients with major hormonal deficits had more abnormal acute computed tomographic findings (P = 0.014), greater acute and chronic body mass index (P < 0.01), and a worse Disability Rating Scale score (multivariate P = 0.04). Compared with the 59 growth hormone-sufficient patients, the 11 patients with GHD or GHI had worse Disability Rating Scale scores (multivariate P = 0.04), greater rates of depression, (90 versus 53%; multivariate P = 0.06), and worse quality of life in the Short Form-36 domains of energy and fatigue (multivariate P = 0.03), emotional well-being (multivariate P = 0.02), and general health (multivariate P = 0.07). CONCLUSION Chronic hypopituitarism warranting hormone replacement occurs in approximately 20% of patients after complicated mild, moderate, or severe traumatic brain injury and is associated with more severe brain injuries and increased disability. GHD and GHI are also associated with increased disability, poor quality of life, and a greater likelihood of depression. The clinical significance of minor hormonal deficits, which occur in almost 30% of patients, warrants further study. Given that major deficiencies are readily treatable, routine pituitary hormonal testing within 6 months of injury is indicated for this patient population.

PITUITARY HORMONAL LOSS AND RECOVERY AFTER TRANSSPHENOIDAL ADENOMA REMOVAL

OBJECTIVETranssphenoidal adenomectomy carries the possibility of new pituitary failure and recovery. Herein, we present rates and determinants of postoperative hormonal status. METHODSAll consecutive patients who underwent endonasal transsphenoidal adenoma removal over an 8-year period were analyzed. Those with previous sellar radiotherapy were excluded. Pre- and postoperative hormonal status (at least 3 mo after surgery) were determined and correlated with clinical parameters using a multivariate statistical model. RESULTSOf 444 patients (median age 45 years, 75% macroadenoma, 19% with multiple operations), 9 had preoperative panhypopituitarism. Of the remaining 435 patients, new hypopituitarism occurred in 5.5% of patients (anterior loss in 5%; permanent diabetes insipidus in 2.1%; including 2 patients who had total hypophysectomy). Of 346 patients with preoperative hormonal dysfunction, 170 (49%) had improved function. “Stalk compression” hyperprolactinemia resolved in 73% of 133 patients; recovery of at least 1 other anterior axis (excluding isolated hypogonadism associated with “stalk compression” hyperprolactinemia) occurred in 24% of 209 patients. Multivariate analysis showed that new hypopituitarism was most strongly associated with larger tumor diameter (P = 0.04). Of 223 patients with an endocrine-inactive adenoma, new hypopituitarism was seen in 0, 7.2, and 13.6% of patients with tumor diameters of <20, 20 to 29, and ≥30 mm, respectively (P = 0.005). Multivariate analysis revealed that resolution of hypopituitarism was related to younger age (39 versus 52 years, P < 0.0001), absence of an intraoperative cerebrospinal fluid leak and, in patients with an endocrine-inactive adenoma, absence of systemic hypertension (24% versus 6%, P = 0.009). CONCLUSIONAfter transsphenoidal adenomectomy, new unplanned hypopituitarism occurs in approximately 5% of patients, whereas improved hormonal function occurs in 50% of patients. The likelihood of new hormonal loss or recovery appears to depend on several factors. New hypopituitarism occurs most commonly in patients with tumors larger than 20 mm in size, whereas hormonal recovery is most likely to occur in younger, nonhypertensive patients and those without an intraoperative cerebrospinal fluid leak.

Vitamin D-mediated hypercalcemia in lymphoma: evidence for hormone production by tumor-adjacent macrophages.

Nearly one‐half of all hypercalcemic patients with lymphoma present with inappropriately elevated circulating concentrations of the active vitamin D metabolite 1,25‐dihydroxyvitamin D (1,25(OH)2D3). However, the cellular source of the vitamin D hormone in lymphomas remains unclear. To address this, we report the case of a 75‐year‐old man with hypercalcemia associated with raised circulating concentrations of 1,25(OH)2D3 and suppressed parathyroid hormone (PTH) levels. Positron emission tomographic (PET) and computed tomographic (CT) imaging revealed the presence of a large lymphoma that was confined to the spleen; subsequent pathological analysis showed that this was an intermediate grade B‐cell lymphoma. After surgical removal of the spleen, serum calcium and 1,25(OH)2D3 levels became normalized within 24 h. Immunolocalization of the vitamin D‐activating enzyme 25‐hydroxyvitamin D3‐1α‐hydroxylase (1α‐hydroxylase) in sections of resected spleen showed that staining was negative in the lymphoma cells but positive in neighboring macrophages. This case study indicates that the hypercalcemia associated with lymphomas may be due, in some instances, to excessive extrarenal production of 1,25(OH)2D3. Furthermore, by using immunohistochemistry to assess the distribution of 1α‐hydroxylase, we have been able to show for the first time that tissue macrophages, rather than actual tumor cells, are the most likely ectopic source of this enzyme. Based on this case study, we propose that the abnormal synthesis of 1,25(OH)2D3 associated with some lymphomas is because of paracrine regulation of tumor‐associated macrophages.

Beta cell function declines with age in glucose tolerant Caucasians.

As type 2 diabetes results from an imbalance between insulin sensitivity and beta cell function, either or both may worsen with age. However, existing data are controversial on the effect of ageing on both insulin sensitivity and beta cell function.

Value of endoscopy for maximizing tumor removal in endonasal transsphenoidal pituitary adenoma surgery

OBJECT Endoscopy as a visual aid (endoscope assisted) or as the sole visual method (fully endoscopic) is increasingly used in pituitary adenoma surgery. Authors of this study assessed the value of endoscopic visualization for finding and removing residual adenoma after initial microscopic removal. METHODS Consecutive patients who underwent endoscope-assisted microsurgical removal of pituitary adenoma were included in this study. The utility of the endoscope in finding and removing residual adenoma not visualized by the microscope was noted intraoperatively. After maximal tumor removal under microscopic visualization, surgeries were categorized as to whether additional tumor was removed via endoscopy. Tumor removal and remission rates were also noted. Patients undergoing fully endoscopic tumor removal during this same period were excluded from the study. RESULTS Over 3 years, 140 patients (41% women, mean age 50 years) underwent endoscope-assisted adenoma removal of 30 endocrine-active microadenomas and 110 macroadenomas (39 endocrine-active, 71 endocrine-inactive); 16% (23/140) of patients had prior surgery. After initial microscopic removal, endoscopy revealed residual tumor in 40% (56/140) of cases and the additional tumor was removed in 36% (50 cases) of these cases. Endoscopy facilitated additional tumor removal in 54% (36/67) of the adenomas measuring ≥ 2 cm in diameter and in 19% (14/73) of the adenomas smaller than 2 cm in diameter (p < 0.0001); additional tumor removal was achieved in 20% (6/30) of the microadenomas. Residual tumor was typically removed from the suprasellar extension and folds of the collapsed diaphragma sellae or along or within the medial cavernous sinus. Overall, 91% of endocrine-inactive tumors were gross-totally or near-totally removed, and 70% of endocrine-active adenomas had early remission. CONCLUSIONS After microscope-based tumor removal, endoscopic visualization led to additional adenoma removal in over one-third of patients. The panoramic visualization of the endoscope appears to facilitate more complete tumor removal than is possible with the microscope alone. These findings further emphasize the utility of endoscopic visualization in pituitary adenoma surgery. Longer follow-ups and additional case series are needed to determine if endoscopic adenomectomy translates into higher long-term remission rates.

Endonasal transsphenoidal surgery and multimodality treatment for giant pituitary adenomas

Objective  Giant pituitary adenomas (≥40 mm) pose a major management challenge. We describe the experience of a single surgeon and a dedicated neuro‐endocrine team with multimodality treatment of these tumours in three specialized institutions.

Chapter 1: pathophysiology of hypopituitarism in the setting of brain injury

The complex pathophysiology of traumatic brain injury (TBI) involves not only the primary mechanical event but also secondary insults such as hypotension, hypoxia, raised intracranial pressure and changes in cerebral blood flow and metabolism. It is increasingly evident that these initial insults as well as transient events and treatments during the early injury phase can impact hypothalamic-pituitary function both acutely and chronically after injury. In turn, untreated pituitary hormonal dysfunction itself can further hinder recovery from brain injury. Secondary adrenal insufficiency, although typically reversible, occurs in up to 50% of intubated TBI victims and is associated with lower systemic blood pressure. Chronic anterior hypopituitarism, although reversible in some patients, persists in 25–40% of moderate and severe TBI survivors and likely contributes to long-term neurobehavioral and quality of life impairment. While the rates and risk factors of acute and chronic pituitary dysfunction have been documented for moderate and severe TBI victims in numerous recent studies, the pathophysiology remains ill-defined. Herein we discuss the hypotheses and available data concerning hypothalamic-pituitary vulnerability in the setting of head injury. Four possible pathophysiological mechanisms are considered: (1) the primary brain injury event, (2) secondary brain insults, (3) the stress of critical illness and (4) medication effects. Although each of these factors appears to be important in determining which hormonal axes are affected, the severity of dysfunction, their time course and possible reversibility, this process remains incompletely understood.

Prevalence of Pituitary Hormone Dysfunction, Metabolic Syndrome, and Impaired Quality of Life in Retired Professional Football Players: A Prospective Study

Hypopituitarism is common after moderate and severe traumatic brain injury (TBI). Herein, we address the association between mild TBI (mTBI) and pituitary and metabolic function in retired football players. Retirees 30-65 years of age, with one or more years of National Football League (NFL) play and poor quality of life (QoL) based on Short Form 36 (SF-36) Mental Component Score (MCS) were prospectively enrolled. Pituitary hormonal and metabolic syndrome (MetS) testing was performed. Using a glucagon stimulation test, growth hormone deficiency (GHD) was defined with a standard cut point of 3 ng/mL and with a more stringent body mass index (BMI)-adjusted cut point. Subjects with and without hormonal deficiency (HD) were compared in terms of QoL, International Index of Erectile Function (IIEF) scores, metabolic parameters, and football career data. Of 74 subjects, 6 were excluded because of significant non-football-related TBIs. Of the remaining 68 subjects (mean age, 47.3±10.2 years; median NFL years, 5; median NFL concussions, 3; mean BMI, 33.8±6.0), 28 (41.2%) were GHD using a peak GH cutoff of <3 ng/mL. However, with a BMI-adjusted definition of GHD, 13 of 68 (19.1%) were GHD. Using this BMI-adjusted definition, overall HD was found in 16 (23.5%) subjects: 10 (14.7%) with isolated GHD; 3 (4.4%) with isolated hypogonadism; and 3 (4.4%) with both GHD and hypogonadism. Subjects with HD had lower mean scores on the IIEF survey (p=0.016) and trended toward lower scores on the SF-36 MCS (p=0.113). MetS was present in 50% of subjects, including 5 of 6 (83%) with hypogonadism, and 29 of 62 (46.8%) without hypogonadism (p=0.087). Age, BMI, median years in NFL, games played, number of concussions, and acknowledged use of performance-enhancing steroids were similar between HD and non-HD groups. In summary, in this cohort of retired NFL players with poor QoL, 23.5% had HD, including 19% with GHD (using a BMI-adjusted definition), 9% with hypogonadism, and 50% had MetS. Although the cause of HD is unclear, these results suggest that GHD and hypogonadism may contribute to poor QoL, erectile dysfunction, and MetS in this population. Further study of pituitary function is warranted in athletes sustaining repetitive mTBI.