TYPE 1 DIABETES: ILLUSTRATIVE CASES – UNCOMPLICATED TYPE 1 DIABETES WITH PREDIABETIC PHASE AND C-PEPTIDE SECRETION

March 8th, 2011 | Diabetes

A 42-year-old Caucasian woman reported that she had an elevated blood glucose transiently in 1980 and gestational diabetes (GDM) in 1995, which required 50 U of insulin daily. For 9 months after delivery, she was managed on diet alone but in 1996 was placed on insulin because of HbA1 c of 7.1 %. Pancreatic islet cell antibody tests were positive. Since then she has maintained HbAlc values in the range of 5.8-6.2%. Usual insulin doses are 5 U NPH before breakfast and 5 U NPH at bedtime with premeal lispro insulin, 1-3U. Her weight is steady at 60 kg; total insulin dose/24 hr = 0.33 U/kg. Blood Dressure and lipid profile are normal. She has had fasting c-peptide levels of 0.6-0.8 ng/dl. She has no retinopathy and urine microalbumin levels are 5-7 mg/24 hours. She has hypothyroidism that is well controlled on 0.125 mg of L-thyroxine/day.

Comment. Type 1 diabetes may follow GDM, particularly in nonobese Patients with positive islet antibodies. The presence of hypothyroidism is another clue to an autoimmune process in the thyroid and pancreas. This Patient has maintained excellent glycemic control on low doses of insulin ’0-33 U/kg), probably because of the presence of residual insulin secretion as shown by fasting c-peptide levels of 0.6-0.8 ng/ml. Although laboratories may vary, we have found that a fasting level of < 1.0 ng/ml is insistent with type 1 diabetes, although higher levels are usually found type 2 diabetes. Experience has indicated that the patient may have a gradual loss of insulin secretion in the future. If so, her insulin requirements will rise and precise glycemic control will be more difficult. Bedtime insulin glargine with premeal lispro or aspart may be tri or she may be placed on insulin pump therapy.

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TYPE 1 DIABETES: ILLUSTRATIVE CASES - UNCOMPLICATED TYPE 1 DIABETES WITH PREDIABETIC PHASE AND C-PEPTIDE SECRETIONA 42-year-old Caucasian woman reported that she had an elevated blood glucose transiently in 1980 and gestational diabetes (GDM) in 1995, which required 50 U of insulin daily. For 9 months after delivery, she was managed on diet alone but in 1996 was placed on insulin because of HbA1 c of 7.1 %. Pancreatic islet cell antibody tests were positive. Since then she has maintained HbAlc values in the range of 5.8-6.2%. Usual insulin doses are 5 U NPH before breakfast and 5 U NPH at bedtime with premeal lispro insulin, 1-3U. Her weight is steady at 60 kg; total insulin dose/24 hr = 0.33 U/kg. Blood Dressure and lipid profile are normal. She has had fasting c-peptide levels of 0.6-0.8 ng/dl. She has no retinopathy and urine microalbumin levels are 5-7 mg/24 hours. She has hypothyroidism that is well controlled on 0.125 mg of L-thyroxine/day.Comment. Type 1 diabetes may follow GDM, particularly in nonobese Patients with positive islet antibodies. The presence of hypothyroidism is another clue to an autoimmune process in the thyroid and pancreas. This Patient has maintained excellent glycemic control on low doses of insulin ’0-33 U/kg), probably because of the presence of residual insulin secretion as shown by fasting c-peptide levels of 0.6-0.8 ng/ml. Although laboratories may vary, we have found that a fasting level of < 1.0 ng/ml is insistent with type 1 diabetes, although higher levels are usually found type 2 diabetes. Experience has indicated that the patient may have a gradual loss of insulin secretion in the future. If so, her insulin requirements will rise and precise glycemic control will be more difficult. Bedtime insulin glargine with premeal lispro or aspart may be tri or she may be placed on insulin pump therapy.*68\357\8*

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