So, the past two days I skipped breakfast to run a basal test. These are the results I got.
June 12:
3:00 - Basal rate 1.30 u/hr
6:30 - 6.3 (113)
7:30 - 7.2 (130)
8:30 - 7.1 (128)
9:00 - Basal rate 0.85 u/hr
9:30 - 6.4 (115)
10:30 - 6.4 (115)
11:30 - 4.8 (86)
12:30 - 4.9 (88)
July 13:
3:00 - Basal rate 1.30 u/hr
6:30 - 6.5 (117)
7:30 - 6.1 (110)
8:30 - 6.3 (113)
9:00 - Basal rate 0.85 u/hr
9:30 - 5.6 (101)
10:30 - 5.4 (97)
11:30 - 6.3 (113)
12:30 - 6.3 (113)
According to John Walsh, if your BG changes by 1.7 mmol/L or more you should adjust your basal rate. Looking at the first day, my blood sugar dropped by 2.4 mmol/L throughout the morning. So that would lead me to think I need to lower my basal rate. Yet the second day I stayed essentially perfectly flat.
So if I lowered my basal rate it might fix that first day, but it would make me go high the second day. And if I don't lower my basal rate I'd be fine on the second day but would easily go low on the first day. These two mornings were literally identical in that I got up and went to work, and in both cases I hadn't eaten or corrected BG in over eight hours.
From the second test I'd say my basal rate is fine - yet if it can drop (and probably rise) by 2.4 mmol/L on some days, then no wonder I have random highs and lows. I'll probably do another test on the weekend to see what happens.