Prevalence of diabetes mellitus is high. It is assumed that in next 20 years the number of people with diabetes will exceed 600 millions (1). Even taking into account only this number it seems obvious that during their life many patients with diabetes will be forced to tackle different problems, connected with special situations. The same is true for treating them doctors. This paper aims to facilitate dealing with these problems, shortly describing some of such situations and providing for each of them short guidelines to follow.

The periods of fasting are usually caused by a religious motivation. In most religions, however, they are rather short, and fast is not total (especially in the case of longer fasting periods the limitations are qualitative, not quantitative). In such cases they are not causing bigger therapeutic problems.

The situation is different in Ramadan. In the period of this fast, which lasts approximately one month, healthy muslim older than 10 years should abstain from any foods and liquids between sunrise and sunset (2). Consequence of this rule is change of the regular eating habits and consuming of only two meals: big evening meal (after sunset) and breakfast (before sunrise). Additionally, Ramadan period moves in consecutive years and may happen at any month. That means that depending on the length of the day, time between the two consumed meals may be shorter or longer. From all the reasons mentioned above Ramadan is a challenge for those diabetic patients who want to follow the fast rules (and from different reasons many if not most of them do that) and treating them doctors. The reader will find below practical statements and guidelines that may help the doctors in our country to deal with muslim patients whose population increases in Poland. Below the reader will find five simple guidelines, based on IDF Ramadan guidelines (3):

In patients with type 2 diabetes metformin should be preferred during Ramadan (optimal is probably long-acting metformin used before the evening meal). Long-acting sulphonylureas are not indicated.

Dipeptylopeptidase-4 inhibitors can be recommended. Many studies confirmed the efficacy of sitagliptin and vildagliptin during Ramadan, incidence of hypoglycemia was low.

In insulin-treated patients with type 1 diabetes in the period of Ramadan it is recommended to reduce the long/intermediate acting insulin dose by 15-30% and to maintain short-acting insulin dose before the evening meal. Long acting insulin analogs are better than intermediate action insulins. Short acting insulin dose before breakfast usually should be also decreased, sometimes substantially. In patients treated with a premixed insulin morning dose should be decreased by 25-50%, and evening dose should be maintained.

In patients with type 1 diabetes during Ramadan a basal bolus regimen should be preferred. Long-acting insulin analogs should preferred over intermediate insulins. Dose modifications should be similar as in type 2 diabetes (see above).

In the light of informations regarding increased frequency of ketotic acidosis after SGLT-2 inhibitors (like canagliflozin) treatment with those drugs during fasting periods, especially quantitative, should not be recommended.

Diabetes is a risk factor of diseases of oral cavity, especially of chronic periodontitis. Inflammation of oral cavity, in turn, is connected with worse diabetes control (4). This vitious circle of inflammation and diabetes may result in comorbidities and organ damage, e.g. hypertension or left ventricular hypertrophy. Therefore it is recommended that patients with diabetes treat chronic periodontitis, and patients with chronic periodontitis maintain good metabolic control of diabetes. This is important also for another reason. Diabetes as well as chronic periodontitis is associated with accelerated atheromatosis and increased cardiovascular risk (5).