Diabetes Review OSCE - Type 1 Diabetes in Young Adult

Case Overview

• Age/Sex: 18-year-old male
• Occupation: College student, semi-professional soccer player
• Setting: Primary care / urgent clinic
• Chief complaint: "Diabetes check-up"

Patient Script

Who I Am

I'm an 18-year-old college student who plays soccer several times a week and works out at the gym.

What Brings Me In

I've been really thirsty and peeing a lot for the last few weeks — my coach said I should get a "diabetes check-up" because I told him about the symptoms.

My Story

About 3–4 weeks ago I started feeling more thirsty than usual and noticed I was drinking a lot of water during practice. Over the next 2–3 weeks I was needing to get up to pee at night 2–3 times, and during the day I was going to the bathroom a lot more than normal. I also felt more tired during training and lost some weight — I used to be around 74 kg, and now I'm about 68 kg over a month. I sometimes get a bit blurry vision when I'm tired, but it clears up. I had a mild sore throat about 10 days ago that went away by itself. I don't have a fever, chest pain, or shortness of breath.

I've been using a new protein shake for the last month and have been pushing heavier weights in the gym — I thought the thirst might be from the workouts or the supplements. I also vape nicotine occasionally when I go out. My uncle has type 2 diabetes, and my dad has high cholesterol.

My Medical Background

• Past medical history: Generally healthy; childhood asthma (infrequent, uses salbutamol inhaler rarely)
• Medications: Occasional use of ibuprofen for muscle soreness; no regular meds
• Allergies: None known
• Social: Lives in shared student housing; vapes occasionally; non-drinker most weeks; sexually active with one partner
• Family history: Paternal uncle with type 2 diabetes; mother alive and well

What I Think & Worry About

• I think maybe I'm dehydrated from training or the new protein shakes.
• I'm worried it might be something serious like diabetes and that I might have to give up playing soccer or take injections.
• I'm worried about how this will affect college and my ability to train.

If You Ask Me About Other Symptoms...

• Thirst: "I'm drinking water all day — a lot more than before."
• Urination: "I need to pee several times during practice and wake up a couple of times at night."
• Weight: "I've lost around 6 kg in the last month without trying."
• Appetite: "My appetite is about the same, maybe a bit more sometimes."
• Energy: "Tired during the day, especially during training."
• Breath: "No bad breath that I noticed — just dry mouth sometimes."
• Nausea/vomiting/abdominal pain: "No real tummy problems, just a bit off my food sometimes."
• Recent infections: "Had a sore throat about 10 days ago but it went away without antibiotics."
• Drugs/supplements: "I started a new protein shake and sometimes take creatine; I vape nicotine occasionally."
• Sexual function: "No problems."

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Clinical Summary

Examination

• General: Thin, athletic young male, alert and oriented
• Vitals: Temperature 36.6°C; heart rate 96 bpm; blood pressure 112/72 mmHg; respiratory rate 14/min; SpO2 99% on air
• Hydration: Mildly dry mucous membranes; slightly decreased skin turgor
• Weight: 68 kg (patient reports ~74 kg 4 weeks ago)
• BMI: 22 kg/m2
• Cardiorespiratory: Heart sounds normal, no murmurs; clear lungs
• Abdomen: Soft, non-tender, no organomegaly
• Neurological: Cranial nerves intact, normal peripheral sensation and power
• Fundoscopy: No obvious retinal hemorrhages; brief visual acuity reduced slightly when symptomatic (patient report)

Investigations

• Fingerstick capillary glucose: 18.6 mmol/L (335 mg/dL) (marked hyperglycemia)
• Venous glucose (random): 17.8 mmol/L (321 mg/dL) (confirms hyperglycemia)
• HbA1c: 10.2% (88 mmol/mol) (indicates chronic hyperglycemia)
• Urine dipstick: Glucose ++/+++; Ketones: trace (no large ketonuria)
• Serum electrolytes: Na 136 mmol/L; K 4.0 mmol/L; Cl 102 mmol/L; HCO3- 24 mmol/L (no metabolic acidosis)
• VBG: pH 7.39, HCO3- 24 mmol/L (no acidosis, DKA unlikely)
• C-peptide: 0.2 ng/mL (low for hyperglycemia) (suggests reduced endogenous insulin)
• Anti-GAD antibodies: Positive (supports autoimmune etiology)

Diagnosis

• Primary diagnosis: New-onset Type 1 diabetes mellitus in a young adult — supported by classic symptoms (polydipsia, polyuria, weight loss), marked hyperglycemia (capillary glucose 18.6 mmol/L), elevated HbA1c (10.2%), low C-peptide, and positive anti-GAD antibodies.

• Differential diagnoses:

  • Type 2 diabetes mellitus: less likely given age, recent weight loss, athletic build, low C-peptide, and positive autoantibodies.
  • Secondary diabetes from medication (e.g., steroids): denied steroid use; labs do not support.
  • Diabetes insipidus: unlikely because of glucosuria and hyperglycemia explaining polyuria.

Management

• Immediate safety/stability:

  • Confirm hemodynamic stability and absence of DKA (already supported by VBG and electrolytes).
  • Provide education that he does not require emergency DKA treatment now but needs prompt diabetes management.

• Initiation of therapy:

  • Start structured insulin regimen (e.g., basal-bolus): initiate long-acting basal insulin plus rapid-acting insulin with meals; dose to be determined by local protocol and endocrinology/diabetes nurse.
  • Teach fingerstick blood glucose monitoring and provide supplies; advise initial frequent monitoring (before meals and at bedtime, consider post-prandial checks).
  • Provide education on insulin injection technique and storage; arrange diabetes nurse/education session same day or next available.

• Additional measures and follow-up:

  • Provide sick-day rules and ketone monitoring advice (given trace ketones now, teach when to seek urgent care).
  • Refer to endocrinology/diabetes clinic urgently (within days) for follow-up and insulin titration.
  • Arrange baseline screening: TSH and thyroid antibodies, coeliac serology (associated autoimmune conditions).
  • Immunizations review: recommend annual influenza vaccine; check tetanus and consider pneumococcal vaccination per local guidance.
  • Discuss sports participation: advise on glucose monitoring before/during/after exercise, carbohydrate snack strategies, and hypoglycaemia management; reassure that with appropriate management he can continue sports.
  • Psychosocial support: discuss concerns about injections, impact on college and sports; offer diabetes education programme and counselling support.

• Safety advice:

  • Provide hypoglycaemia management plan and glucagon prescription/training if indicated later with intensive insulin therapy.
  • Discuss driving and sport safety precautions related to hypoglycaemia per local regulations.

Key Learning Points

• Type 1 diabetes can present in late adolescence/young adulthood with the classic triad of polyuria, polydipsia, and weight loss; confirm with hyperglycemia and HbA1c.

• Distinguish type 1 from type 2 by clinical context and tests: low C-peptide and positive islet autoantibodies (e.g., anti-GAD) support autoimmune (type 1) diabetes.

• Early management focuses on confirming stability (exclude DKA), initiating insulin, diabetes education (monitoring, injection technique, sick-day rules), and arranging timely multidisciplinary follow-up (endocrinology, diabetes nurse, dietitian).