Table 2.
Clinical and biochemical characteristics of Type 1 diabetes mellitus, Type 2 diabetes mellitus and ketosis-prone diabetes mellitus adult patients.
| Characteristics | T2DM | T1DM | KPDM |
|---|---|---|---|
| Clinical | |||
| Mean age at presentation (years) | Fifth decade | Third to fourth decade of life | Third to sixth decade of life |
| Ethnicity | Predominantly AA and Hispanics | Predominantly Caucasians and AA | Predominantly AA and Hispanics |
| Presentation | Moderate hyperglycemia | DKA or hyperglycemia | Usually as DKA or severe hyperglycemia |
| Duration of symptoms at presentation (weeks) | 9 | <4 | Acute, usually <6 |
| Acanthosis nigricans | Present | Absent | Present |
| Ability to achieve control with oral hypoglycemic | Variable | None | Initially, up to 75% after discontinuation of insulin; however, many require insulin again over time |
| Remission from insulin | Frequent | Rare | Frequent |
| Course | Loss of insulin secretion and worsening sensitivity | Progressive decline in insulin secretion | Remitting and relapsing course with overall progression similar to T2DM |
| BMI (kg/m2) | Overweight to obese | Lean | Overweight to obese |
| Male:female | 1:1 | 1:1 | 1.5:3 |
| Family history (%) | 30–80 | 30 | 80–100 |
| Biochemical | |||
| Primary defect | Insulin secretion and sensitivity | Lack of insulin | Acute defect in insulin secretion and sensitivity which improves with near-normoglycemic resolution |
| Markers of β-cell autoimmunity | Absent | Present | Absent |
| HLA genotype susceptibility | Absent | Present | Variable among study cohorts |
| Fasting C-peptide | Normal | Depressed | Normal |
| Insulin secretion (C-peptide response to mixed meal) upon presentation | Present | Absent | Present but lower than T2DM |
| Insulin secretion (C-peptide response to mixed meal or glucose) at follow-up | Similar to KPDM | Absent | Present |
| Insulin sensitivity at presentation | Decreased compared with obese nondiabetics | Decreased compared with obese nondiabetics | Decreased compared with obese nondiabetics |
| Insulin sensitivity at follow-up | Similar to obese nondiabetics | Increased as compared with T2DM/KPDM | Similar to obese nondiabetics |
| Development of ketosis | Resistant to ketosis | Associated with lack of insulin | Preceded by hyperglycemia and elevated FFA |
| Ref. | [7,8,33,60–64] | [7,8,33,58,60,65–69] | [7–12,17,24,25,31,33,56,60,70] |
AA: African–American; DKA: Diabetic ketoacidosis; FFA: Free fatty acid; KPDM: Ketosis-prone diabetes mellitus; T1DM: Type 1 diabetes mellitus; T2DM: Type 2 diabetes mellitus.