dependent upon the twin cycles of glucose entering the bloodstream, and insulin allowing appropriate uptake into the body cells. Both aspects can require management. Another issue that ties along with the glucose cycle is getting a balanced amount of the glucose to the major organs so they are not affected negatively. Complexities The main complexities stem from the nature of the feedback loop of the glucose cycle, which is sought to be regulated: The glucose cycle is a system which is affected by two factors: entry of glucose into the bloodstream and also blood levels of insulin to control its transport out of the bloodstream As a system, it is sensitive to diet and exercise It is affected by the need for user anticipation due to the complicating effects of time delays between any activity and the respective impact on the glucose system Management is highly intrusive, and compliance is an issue, since it relies upon user lifestyle change and often upon regular sampling and measuring of blood glucose levels, multiple times a day in many cases It changes as people grow and develop It is highly individual As diabetes is a prime risk factor for cardiovascular disease, controlling other risk factors which may give rise to secondary conditions, as well as the diabetes itself, is one of the facets of diabetes management. Checking cholesterol, LDL, HDL and triglyceride levels may indicate hyperlipoproteinemia, which may warrant treatment with hypolipidemic drugs. Checking the blood pressure and keeping it within strict limits (using diet and antihypertensive treatment) protects against the retinal, renal and cardiovascular complications of diabetes. Regular follow-up by a podiatrist or other foot health specialists is encouraged to prevent the development of diabetic foot. Annual eye exams are suggested to monitor for progression of diabetic retinopathy. Early advancements Late in the 19th century, sugar in the urine (glycosuria) was associated with diabetes. Various doctors studied the connection. Frederick Madison Allen studied diabetes in 1909–12, then published a large volume, Studies Concerning Glycosuria and Diabetes, (Boston, 1913). He invented a fasting treatment for diabetes called the Allen treatment for diabetes. His diet was an early attempt at managing diabetes. Blood sugar level Blood sugar level is measured by means of a glucose meter, with the result either in mg/dL (milligrams per deciliter in the US) or mmol/L (millimoles per litre in Canada and Eastern Europe) of blood. The average normal person