Sleep & CPAP Report — 2026-08-30

🚩 Flags

• 3-night OA streak broken. OA fell to 8 tonight after 14 → 12 → 15 on Aug 27–29. AHI dropped to 1.29 (vs 3.07 last night; −58%), the lowest since Aug 23. Hypopneas went to 0 (from 6) — first zero-H night since Aug 13. The three-night trigger yesterday's report flagged is not extending to four.
• Leak spiked to a trailing-30d high. Leak_Avg 1.71 L/min (vs 30d 0.80; +114%) and Leak_90th 7.2 L/min (vs 30d 2.40; +200%) are both the highest in the last 30 nights. Leak_Max 16.8 is elevated but not extreme. Mask fit was clearly worse tonight than any other night this month, yet events came in low — consistent with the historical pattern that this profile's event load doesn't track mask fit.
• Deep sleep at a 10-night low. 9.2% tonight vs 7d 12.50% (−3.3 pp) and 30d 13.62% (−4.4 pp). Only Aug 20 (7.7%) has been lower in the trailing month. REM held strong at 27.80% and awake time stayed low (5.5 min), so total quality is still decent — but the deep-sleep dip is notable given tonight's high leak.
• Central apnea returned (mild). CA=1 after CA=0 last night. Not the 2–3/night cluster we saw Aug 25–28; treat as noise unless it repeats.
• Flow limitation eased. Min >0.10 = 18.8 min tonight vs 35.6 last night (~half); FL_P95 dropped from 0.13 → 0.17 wait — FL_P95 is actually higher tonight (0.17 vs 0.13) but duration above the 0.10 threshold nearly halved. Interpretation: fewer sustained flow-limit episodes, but the ones that occurred were narrower peaks.

Summary Table — Night of 2026-08-30

Metric	Value
Sleep start	22:24:23 CDT
Time in bed	413.5 min (6h 53m)
Total sleep	407.9 min (6h 48m)
Sleep efficiency	98.7%
Awake time	5.5 min
Core (N1+N2) sleep	256.9 min / 63.0%
Deep (N3) sleep	37.6 min / 9.2%
REM	113.4 min / 27.8%
CPAP usage hours	6.98
Session count	1
AHI	1.29
RDI	1.43
Obstructive apneas (OA)	8
Hypopneas (H)	0
Central apneas (CA)	1
Unclassified apneas (UA)	0
RERA	1
Pressure avg	8.00 cmH₂O
Pressure min	4.00 cmH₂O
Pressure 90th	10.10 cmH₂O
Pressure max	11.06 cmH₂O
Leak avg	1.71 L/min
Leak 90th	7.2 L/min
Leak max	16.8 L/min
Flow-limit p95	0.17
Flow-limit min >0.10	18.8
Flow-limit min >0.20	2.4

Trailing Averages Comparison

Metric	Tonight	7-day avg	Δ vs 7d	30-day avg	Δ vs 30d
AHI	1.29	2.03	−36%	1.86	−31%
OA count	8	9.57	−16%	8.43	−5%
H count	0	2.71	−100%	3.00	−100%
CA count	1	1.29	−22%	1.03	−3%
Leak_Avg (L/min)	1.71	0.69	+148%	0.80	+114%
Leak_90th (L/min)	7.2	1.89	+281%	2.40	+200%
Pressure_Avg	8.00	7.17	+12%	7.47	+7%
Pressure_90th	10.10	9.65	+5%	10.01	+1%
Usage hours	6.98	6.68	+4%	6.72	+4%
Deep sleep %	9.2%	12.5%	−3.3 pp	13.6%	−4.4 pp
REM %	27.8%	26.9%	+0.9 pp	24.2%	+3.6 pp
Awake min	5.5	7.5	−27%	15.1	−63%
Total sleep (min)	407.9	387.0	+5%	384.0	+6%

Week-over-Week Trend

Metric	Recent 7d (Aug 24–30)	Prior 7d (Aug 17–23)	Direction
AHI	2.03	1.85	↑ +9.7%
OA count	9.57	8.86	↑ +8.0%
H count	2.71	3.14	↓ −13.6%
CA count	1.29	0.43	↑ +200%
Leak_Avg	0.69	0.97	↓ −28.9%
Leak_90th	1.89	2.23	↓ −15.2%
Pressure_Avg	7.17	7.81	↓ −8.2%
Pressure_90th	9.65	10.56	↓ −8.6%
Deep sleep %	12.50	12.85	↓ −2.7%
REM %	26.88	21.69	↑ +23.9%

Week-over-week picture unchanged from yesterday: leak trending favorable at the weekly level (even though tonight was an outlier), event load still slightly above the prior week's baseline, pressure delivery running below prior week. Tonight's numbers didn't shift the weekly averages materially.

Recent 10-Night Detail

Date	AHI	OA	H	CA	Leak_Avg	Leak_90th	P_Avg	Hours
2026-08-30	1.29	8	0	1	1.71	7.2	8.00	6.98
2026-08-29	3.07	15	6	0	0.93	3.6	8.23	6.85
2026-08-28	2.43	12	1	3	0.28	0.0	6.08	6.58
2026-08-27	3.17	14	4	3	0.83	3.6	7.59	6.63
2026-08-26	1.33	7	1	1	0.72	0.0	7.09	6.77
2026-08-25	1.61	7	2	2	0.73	2.4	7.05	6.85
2026-08-24	1.81	9	3	0	0.37	0.0	6.63	6.63
2026-08-23	0.77	3	2	0	0.94	3.6	7.53	6.48
2026-08-22	1.54	8	2	0	0.74	0.0	8.00	6.48
2026-08-21	2.82	15	6	1	0.20	0.0	7.68	7.80

Four of the last ten nights (Aug 20 falls off; Aug 21, 27, 28, 29) hit ≥12 OA — same frequency as yesterday. Tonight breaks the sequence but doesn't reset the trailing rate.

Correlation Analysis (46 matched nights)

Pair	the user r
AHI ↔ Deep sleep %	−0.05 (none)
AHI ↔ Awake minutes	−0.19 (weak negative)
Leak_Avg ↔ Deep sleep %	−0.13 (weak negative)
Leak_Avg ↔ Awake minutes	−0.23 (weak negative)
Leak_90th ↔ Deep sleep %	−0.15 (weak negative)
Leak_90th ↔ Awake minutes	−0.14 (weak negative)

High- vs low-leak bucket comparison (split at Leak_Avg median = 0.72 L/min):

• High-leak nights (n=22): mean deep sleep 14.19%, awake 12.0 min
• Low-leak nights (n=24): mean deep sleep 14.61%, awake 18.0 min

Interesting: the awake effect goes the opposite direction from intuition — nights with higher leak actually average slightly less awake time, though deep sleep is marginally lower. Tonight fits: highest leak of the month, but only 5.5 min awake and 9.2% deep. The persistent pattern remains that leak weakly depresses deep sleep without disrupting continuity.

Interpretation

Tonight is essentially the inverse of yesterday's night. Aug 29 was: normal-good leak, high events, high flow limitation, low deep. Aug 30 is: high leak, low events, moderate flow limitation, low deep. Both nights had short awake time and decent efficiency.

Reading across the two:

1. The event load is not tied to mask fit. Two nights back-to-back with opposite leak profiles produced opposite event counts. If leak were driving the OA cluster, tonight would have been worse, not better. This is more evidence that whatever caused the Aug 27–29 spike is not device-side.
2. The three-night OA cluster looks self-limited. No fourth-night extension. Absent another supra-baseline night in the next 2–3, the earlier flag can be down-ranked.
3. Deep sleep dip is the softer concern tonight. 9.2% is the second-lowest in the trailing month. Two consecutive nights below 12% (Aug 29 → 30) is a mild negative trend. Watch whether tomorrow returns toward the 13.6% baseline.
4. The leak spike itself is worth noting. Leak_90th 7.2 is roughly 3× baseline. Isolated night at that level is usually mask position (side-sleeping onto the mask, cushion needing a wipe, headgear slipping). Not concerning as a one-off; would matter if it repeats 2–3 nights running.

Watch items rolling forward: any fourth ≥12-OA night this week (unlikely based on tonight), a repeat leak elevation tomorrow, or a third consecutive sub-12% deep sleep night.

Subjectively: likely a fine night — 6h 48m sleep, 5.5 min awake, REM 27.8%. The metrics that would fragment perceived sleep (awake time, efficiency) are excellent.

Caveats

• SpO2/pulse columns remain empty (device not recording those channels).
• Sleep-stage percentages are Apple Watch estimates (accelerometer + HR), not lab EEG.
• Flow-limit p95 comparison to yesterday noted the p95 rose while duration above 0.10 fell — this reflects that a small number of narrow, high-amplitude flow-limit events occurred tonight vs. a longer, lower-plateau pattern last night. Not a contradiction.
• Single CPAP session — no mid-night mask-off artifacts to filter.
• AHI 1.29 is well within the "well-controlled" clinical range (<5); all flags in this report describe deviation from the user's personal baseline, not absolute severity.