Ketosis Prone Type 2 Diabetes Mellitus (KPT2D): An Unusual Presentation in a Middle-Aged Male Precipitated by Influenza A infection.

Abstract

The clinical importance of diagnosing KPT2D is to distinguish it from T1DM, which requires lifelong insulin treatment. KPT2D patients are often middle-aged (Males > Females), positive family history, overweight, and with dysmetabolic traits (abdominal obesity, hypertension, dyslipidemia), however presenting with acute hyperglycemic emergency. There is an obvious risk for misclassification as T1D, and being unnecessarily and chronically—perhaps for a lifetime—on insulin treatment, and subsequently to the risks and disadvantages of insulin therapy: hypoglycemia, weight gain, impact on quality of life (requirements for frequent self-monitoring and multiple daily injections), career limitations and low self-esteem.

Case description- A 26-year-old married male presented with acute onset history of fever and dry cough for 5 days, multiple episodes of vomiting for 3 days and altered mental status since last 2 days. On admission, general physical examination revealed GCS- E3V4M6, tachycardia, tachypnoea, normal blood pressure, fruity breath odour, dry mucous membranes, grade 3 acanthosis nigricans on neck extending onto lateral margins (Figure 1) and acanthosis nigricans over knuckles over both hands (Figure 2). Systemic examination revealed B/L coarse crepitations and diffuse wheeze on chest examination, with normal cardiovascular and neurological examination. Biochemical investigations revealed hyperglycemia (random BG- 510 mg/dl & 559 mg/dl), ketonemia (Serum ketones- 5.5 mmol/L), high anion gap metabolic acidosis (pH- 7.080, HCO³- 7.5), prerenal azotemia with normal liver function tests and hemogram. With a diagnosis of severe diabetic ketoacidosis, patient was started on intravenous fluids and regular insulin infusion with regular monitoring of blood glucose, serum electrolytes and renal function tests. In view of bilateral reticular shadows on chest X-ray and history of upper respiratory tract infection, patient was tested for Covid 19 and Influenza RT-PCR and came out to be positive for Influenza A. Patient was shifted to multiple subcutaneous insulin injections after correction of ketoacidosis. There was no family history of DM. Serum C-peptide levels during the acute illness were 0.58 ng/mL; while fasting C-peptide levels done after resolution of DKA and acute stress state revealed a value of 1.86 ng/mL. Anti GAD 65 antibodies came out to be negative. Therefore, a diagnosis of Ketosis Prone Type 2 Diabetes Mellitus was made and patient was discharged on 2 doses of premix insulin and insulin sensitizers (Metformin), with subsequent plan of tapering the insulin therapy and intensification of Oral Antidiabetic Drugs (OADs).

Discussion- KPT2D or Flatbush Diabetes is an emerging form of diabetes mellitus that usually presents with DKA or unprovoked ketosis in patients who lack the typical phenotypic features of T1DM. These patients are middle aged, obese and usually present with defect in insulin secretion and decreased insulin sensitivity in the setting of a physiological stressor. Treatment of the precipitating cause, which in many cases is an infection, along with initiation of insulin will lead to an improvement in β-cell function and insulin sensitivity, as seen in current case by rising serum C-peptide levels. This case underscores the importance of awareness regarding the rise in incidence of this atypical phenotype of diabetes and need for increased vigilance on the part of treating clinicians.