Multicentric, observational, cross-sectional study in Italy. The aims are to evaluate the daily metformin prescribed dose and the impact of renal function and concomitant medication in diabetic patients over 65 years.

The study was commissioned by the Italian Association of Clinical Endocrinologists (Association of Medical Endocrinologists - AME) and approved by the Ethical Committee of Cuneo Hospital. The research was open to all specialists taking care of patients with diabetes in Italy.

The primary endpoint was the evaluation of metformin dosage. Secondary endpoints were the relationship between the metformin dosage and the renal filtration rate and the relationship between the metformin dosage and the concomitant medication.

An ad hoc form was developed and used to record all medical findings. The form was emailed to all participating centers who then emailed or faxed it back to the investigator's data manager. Data were checked for accuracy.

The following data were required: age, gender, body weight and height, diabetes duration, type of metformin (classical/slow), daily dosage of metformin, reported side effects,concomitant medications.

Serum creatinine and HbA1c levels obtained within the previous two months were also required.

Each participating center recruited about 50 diabetic outpatients. Inclusion criteria were as follows: adult outpatients ≥ 65 years with T2 diabetes mellitus, using metformin for at least six months, usually assuming three daily meals, and capable of informed consent.

Inclusion Criteria:

• adult outpatients (≥65 years);
• T2 diabetes mellitus;
• Taking metformin for at least six months;
• assuming three daily meals;
• capable of informed consent.

Exclusion Criteria:

• severe liver or renal failure (eGFR <30 mL/min/1.73 m2);
• hospitalization for any cause in the last six month;
• glucocorticoid treatment in the last six month;
• oncologic treatment in the last six month;
• Ramadan in the last six months.

All diabetic patients respecting eligibility criteria