Case Report/Case Presentation
Our case is 35 years old female known
to have type 2 Diabetes Mellitus on metformin 1 gm daily. In 2014, the
patient presented with fatigue and weight gain. Work up showed TSH 23
Miu/l (0.5 to 5.5 Miu/l) and T4 of 15 Miu/l (9 to 21 Miu/l). The patient
was diagnosed with subclinical hypothyroidism and started on
levothyroxine treatment. Starting dose was 25 mcg daily and the patient
was followed to monitor her symptoms and TSH level.
In next follow up appointments, the patient reported some improvement in
her symptoms. however, her TSH level was persistently elevated. Thyroxin
dose was gradually built up till a dose of 100 mcg was reached over 4
years period but TSH level wasn’t inhibited. Other labs including
complete blood count, renal function, liver function and lipid profile
were within normal limits.
Appointment in November 2018, TSH was 20 miu/L. levothyroxine dose was
subsequently increased to 150 mcg daily. Few weeks later, the patient
reported hyperthyroid symptoms including insomnia, tremors and
palpitation. Repeated thyroid function test showed TSH of 6.6 miu/L and
T4 level was significantly high (30 mic/L). the dose was reduced to 100
mcg and antibodies were requested.
Next appointment following reduction of levothyroxine dose, her insomnia
and palpitations improved. Repeated labs showed TSH 34 miu/L, T4 17
miu/L, antithyroid peroxidase antibody > 600 IU/ml (0 to 34
IU/ml), antithyroglobin antibody 489 IU/ml (0 to 115 IU/ml) and TSH
receptor antibody 0.8 IU/L (0 to 1.7 IU/L).Figure 1 showed TSH, T4 and
T3 throughout treatment with various doses of levothyroxine from time of
diagnosis ( 2013) till 2020,