Advanced Hybrid Closed Loop System (AHCL) in Older Patients With Type 1 Diabetes Mellitus

The primary objective of this study is to evaluate whether the AHCL (MiniMed 780G) system improves glucose indices in older (above 60 years of age) individuals with Type 1 diabetes mellitus.

Glucose differences between the groups will be monitored and evaluated by difference in the percentage of time spent within range with sensor glucose (SG) between 70-180 mg/dL (Primary outcome), time in hyperglycemic range SG > 250 mg/dL , SG > 180 mg/dL, time in hypoglycemic range with SG < 70 mg/dL , SG < 54 mg/dL as well as difference in the glycemic variability, mean glucose level and change in HbA1c levels.

The test measures the ability of a person to: stand up, walk, turn around and sit down safely in a timely manner. The test examines most mobility skills. The participant is told to get up from a chair with handles, walks 3 meters, turns, walks back, and sit down again. The score is according to the length of time in seconds to complete the task. The score is categorized according to the risk for falls and independent walking. The following cut-offs are conventionally used: less than14 seconds = independent mobility; 15-20 seconds= semi-independent mobility may have a some what increased risk for falls & needs further evaluation some may need a walking aid; 20-30 seconds= dependent mobility: need help walking, 50% with a cane, 40% walker, 10% supervision. Some will need help in transfers, and most will require help using the toilet.

The six-minute walk test (6MWT) measures the distance an individual is able to walk over a total of six minutes on a hard, flat surface. The goal is for the individual to walk as far as possible in six minutes. The individual is allowed to self-pace and rest as needed as they traverse back and forth along a marked walkway. The six minute walk distance in healthy adults has been reported to range from 400m to 700m. People with lower vs. higher scores on the 6 minute walk are at higher risk for falls, disability, frailty, hospitalization and death. There is no conventional cut offs, however as with other tests, severe impairment may be defined as two standard deviations below the norm.

The Four Square Step Test (FSST) evaluates dynamic balance in a high functional level and features walk forward backwards left and right above two, 90 cm and 2.5 cm high long sticks that divide the floor into four squares. The participant is stands in square 1 facing no. 2 square. The goal is to walk as quickly as possible in all the squares in the following order: from 1 to- 2,3,4,1,4,3,2 and 1 without touching the sticks. The score is the time required to complete the entire route. Sever physical impairment is considered less then 15 seconds, Mild physical impairment is considered 10.14- 14.59 seconds, intact physical impairment is considered less then 10.14 seconds.

The maximum grip strength is examined utilizing the Jammer dynamometer. The test is conducted in a neutral hand position and repeated three times. The score is the average strength in kg this is compared to the general population according to age and gender. There is no conventional cut offs, however as with other tests, severe impairment may be defined as two standard deviations below the norm.

Fried scale criteria is used for identifying frailty in older people. Frailty is defined as the presence of at list three components. i. Weight loss: More then 10 pounds unintentional weight loss in the past year (not due to dieting or exercise).

ii. Poor endurance and energy: as indicated by self-report of exhaustion. Self-report exhaustion, identified by two questions from the CES-D scale.

iii. Low Physical Activity level: kilocalories expended per week, calculated adjusted according to age and gender.

iv. Walk time: over seven seconds to pass three meters

Cognitive function will be assessed using the Montreal Cognitive Assessment (MOCA), a rapid screening tool for mild cognitive dysfunction. It assesses different cognitive domains such as: attention and concentration, executive functions, memory, language, visuoconstructional skills, conceptual thinking, calculations, and orientation. A MoCa score<21 was defined as severe cognitive impairment (probable dementia). A MoCA score between 21-25 was defined as mild cognitive impairment.

The Digit Symbol Substitution Test (DSST): a subtest of the Wechsler Adult Intelligence Scale (3rd Edition) and pertains to a wide array of cognitive domains such as visual-motor speed and coordination, capacity for learning, attention, concentration and short term memory. The DSST gets a raw score between 0 and 90 which can then be converted to a standardized score with a mean score of 10 and a standard deviation of 3.

The WHO-5 wellbeing questionnaire asses emotional status. Who 5 gets a raw score of 0 to 25 which is then multiplied by 4 to convert the score to a continuum between 0 (worst imaginable quality of life) to 100 (best imaginable quality of life). A score of ≤50 indicates poor wellbeing and suggests further investigation into possible symptoms of depression. A score of 28 or below is indicative of depression.